Why does my phone cling to the far access point instead of roaming?

Because the client — not the access point — makes the roaming decision. Apple's deployment documentation states the thresholds for its devices: iPhone and iPad begin looking for a better AP at −70 dBm, Macs at −75 dBm, and a candidate must be stronger by 8 dB (while transmitting) or 12 dB (idle) to win; Ubiquiti's own guidance agrees that clients roam around −70 to −75 dBm and usually only when another AP has far greater signal strength. If your near AP doesn't beat the far one by that margin — because the far AP is shouting at High power — the phone is behaving exactly as designed. The fix is power symmetry and density, not forcing: a Minimum RSSI of −67 dBm (popular folklore) sits above the iPhone's own −70 trigger, so the AP would disconnect the phone before the phone starts scanning.

What Wi-Fi speed should I actually expect on UniFi?

Ubiquiti's own speeds guidance puts realistic throughput at roughly 50 to 60 percent of the negotiated link rate, and describes 150 to 600 Mbps as realistic per client on a gigabit plan. The negotiated rate shown in the controller is a ceiling under ideal conditions, not a measurement. Before blaming Wi-Fi at all, run a wired speed test at the switch: if the wired baseline is slow, the disease is the WAN or the gateway, and no Wi-Fi setting will touch it.

Should I set Minimum RSSI to fix sticky clients?

Last, if at all. Ubiquiti's current settings documentation says Minimum RSSI is generally not recommended unless you run a high-density deployment, offers −80 dBm only as a starting point after a site survey, and warns it is set per AP and per radio. Applied early or aggressively (folklore values like −67 or −70) it disconnects clients whose own roam logic hasn't yet looked for a new home — converting a sticky client into a dropped one. Channels, widths, transmit-power symmetry, band steering/BSS transition and the airtime controls all come first.

UniFi · Wi-Fi performance · Fix

Wi-Fi is slow and clients cling to the wrong AP — stop changing settings, start measuring

First published 20 October 2026 · Method and figures from Ubiquiti's troubleshooting, airtime, speeds and DFS documentation, plus Apple's deployment reference for the client-side half of the story. Every setting below names its verify and its revert.

Do not fix the wrong thing first. The roaming decision belongs to the client. Apple's own deployment documentation: an iPhone starts shopping for a better AP at −70 dBm — and the candidate must beat the current AP by 8 dB (busy) or 12 dB (idle) to be chosen. If your far AP is shouting at High power, the phone isn't broken. It's obeying physics and Apple. Your job is to change the margin, not to force the phone.

Step 0 — measure first (three instruments, no settings)

Wired baseline: speed-test from a cable at the switch (WiFiman's device→gateway test does the same job). Slow wired = the WAN/gateway is your disease; this page no longer applies.
The walk: WiFiman's Signal view, room by room: RSSI, band, serving AP — and stand on the seam between two APs and watch when (if) you roam. Ubiquiti's own scale: above −60 excellent · −60…−70 acceptable · −70…−75 “clients should begin to roam” · below −80 instability.
The AP-side look: Radios → Coverage shows per-client signal and the AP/Client Signal Balance — a “Poor” balance is the shouting-AP/whispering-phone asymmetry made visible. AirView shows two bars: orange = interference, blue = your own airtime. Read historically with Ubiquiti's key: high airtime + high interference = channel disease; high airtime + low interference = load/multicast disease.

Name your disease

Evidence	Disease	Ladder rungs
Fine near APs, dead in specific rooms regardless of settings	Coverage hole	Placement/AP — not settings (§FAQ)
AirView orange bar high; neighbours on your channel	Co-channel interference	1–2
Clients at −75 hanging on, near AP visible but <8 dB better	Sticky client (power asymmetry)	3, then 4
Airtime high, interference low; many chatty devices	Airtime hog (multicast/broadcast + legacy rates)	5
Fast near the gateway AP, slow behind the mesh node	Uplink ceiling	Wire it (Pack #23's ≥50%/hop law)
Wired baseline already slow	WAN	Gateway/ISP guides, not this one

The settings ladder — in order

Channels & widths. 2.4 GHz: 20 MHz, channels 1/6/11 only. 5 GHz: 40 MHz in offices, 80 at home (Ubiquiti's own guidance — its speeds page pushes 80 while its connectivity guide says 40 for offices; the goal decides, and neighbouring networks vote too). 6 GHz can go wide (160–320) where spectrum is clean. DFS caveat from Ubiquiti's text: on a radar hit the AP stops broadcasting on that channel immediately, boot/switch waits run 1–10 minutes, and a detected channel is off-limits ≥30 minutes — a DFS channel that “keeps vanishing” is behaving legally. Verify: AirView orange bar falls. Revert: note the old plan first.
One plan, all APs: adjacent APs on different channels; same channel on neighbours is the interference you just measured.
Transmit-power symmetry. High in low-density, Medium in offices (Ubiquiti) — and above all matched to client reality: your phone transmits far weaker than your AP. Lowering the shouting far AP is what creates the 8–12 dB margin the client's roam logic demands. Verify: the seam test roams earlier; Signal Balance improves.
Steering & roaming assists. Band Steering stays enabled (Ubiquiti; now SSID-level via BSS transition). BSS Transition on: it “encourages” roam-ready clients (old devices may ignore it). Fast Roaming (802.11r): Ubiquiti “strongly recommends” on — with its two printed caveats: it conflicts with Switch Port Isolation, and clients that can't do 802.11r belong on a separate legacy SSID with it off. Verify: walk-test calls/Teams through the seam.
Airtime controls. Multicast & Broadcast Control and Minimum Data Rate Control are the documented levers (raising minimum rates trims multicast/broadcast airtime and “encourages clients to roam sooner”; Ubiquiti warns 802.11b-era devices may lose connectivity — they were the airtime problem). Multicast Enhancement is the gentler first step. Note: older guides prescribe an “Airtime Fairness” toggle; it does not appear in Ubiquiti's current settings documentation — this ladder teaches what exists.
Minimum RSSI — last, surveyed, gentle. Only with survey numbers in hand, per-AP/per-radio, starting at −80 dBm (Ubiquiti's starting point, unchanged across versions) — and never at folklore values: −67 dBm boots an iPhone before its own −70 trigger starts scanning. If rung 3 fixed the margin, this rung stays empty.

What NOT to do

The reflex	Why it backfires
Max transmit power everywhere	Manufactures sticky clients and co-channel noise; the phones can't shout back
320 MHz “because Wi-Fi 7”	One giant channel in shared spectrum = you become everyone's interference
Minimum RSSI −67/−70 from a forum	Sits at/above client roam triggers — drops, not roams
Ten settings at once	Unattributable results, loops included (see the provisioning guide)
Chasing the negotiated-rate number	Ubiquiti: real throughput ≈ 50–60% of PHY rate; 150–600 Mbps per client on gigabit is realistic

FAQ

All settings perfect, one room still dead.

Then it was never a settings problem: coverage is geometry. Move the AP, add an AP (wired if humanly possible — mesh rules), or accept the room's physics. No toggle bends radio waves around a masonry wall.

Android/Windows clients — same thresholds?

Their vendors don't publish roam thresholds; anyone quoting a universal “−70 law” beyond Apple/Ubiquiti's corroborated range is embroidering. The margin principle (near AP must win decisively) holds across clients even where exact numbers don't.

One ancient device slows everyone — real?

Yes, qualitatively: airtime is shared, and slow-rate transmissions (legacy clients, distant clients) occupy more of it; that's the documented mechanism behind rung 5. No exact “one device = X% slower” multiplier exists in Ubiquiti's material, so this guide doesn't print one.

Sources

Ubiquiti Help Center — WiFi Troubleshooting Guide, Airtime Utilization, Maximizing Wireless Speeds, DFS Channels, SSID & AP Settings Overview (signal scale, widths, power, DFS behaviour, steering/roaming toggles, airtime controls, Minimum RSSI stance) · Apple — Wi-Fi deployment reference (roam triggers −70/−75 dBm, 8/12 dB candidate margins) · This site's Packs #21/#23/#25 (6 GHz conditions, mesh law, Channel AI clearance).

Verification note: settings wording and the dBm scale were re-read from Ubiquiti's current documentation on 20 October 2026; Apple's thresholds from Apple's deployment documentation. Android/Windows thresholds and any per-device slowdown multiplier were NOT found in primary sources and are not claimed.

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