@ARGamingPK1 Thank you for the reply. However, as shown in the screenshot, Fast Roaming is already disabled on my system, so this is not the root cause.

Based on other threads in this community (topics #799958 and #712394), the issue appears to be related to the 2.4 GHz band being used as backhaul, causing interference with IoT client devices. A beta firmware that includes a setting to disable 2.4 GHz backhaul was provided to some users and resolved the problem.

Could @David-TP  or another TP-Link staff member please assist with providing the beta firmware for Deco XE75 V1.0 (firmware 1.4.5)?

Thank you.

  @Javito_ar  I have the same problem, btw ¿argentino?, me too.  We need firmware 1.4.999 beta working for V1-

  @Solla-topee 

Hi @Solla-topee, thanks for the reply. Here are the details:

Setup: 2x Deco XE75 V1 (one main, one satellite) + 3x Deco S7 satellites, distributed
around the house, wireless backhaul. IoT Network feature created from the Deco app.

1. Client counts and bands

- IoT Network: ~27 clients, and yes, it is 2.4GHz-only (all of them are 2.4GHz-only

  devices anyway). Breakdown: 8 Wi-Fi cameras (EZVIZ), 6 mains-powered smart

  plugs/wall switches/DIN-rail breakers (Tuya), ~10 battery-powered sensors

  (door/window contact + plant sensors, ESPHome/Tuya — these deep-sleep and only

  associate for a few seconds when they wake), 1 smart pet device, 1 A/C, 1 3D printer.

  So concurrently associated at any moment it's typically ~15-18 clients.

- Main network: ~8-10 clients (phones, laptops, TV), almost all on 5GHz/6GHz.

  Desktop PC and my Home Assistant server are wired to the main Deco.

2. Disconnect behavior — three distinct patterns, all exclusive to the 2.4GHz IoT network:

a) Devices that drop and NEVER reconnect on their own (the worst one): two
   mains-powered devices (a smart plug and a 3-gang wall switch) lose Wi-Fi
   association and stay offline for HOURS. They disappear from the client list —
   it is a full Wi-Fi disconnect, not "connected without internet". The only ways
   to restore them: physically power-cycle the device (unplug 30s), or
   Block + Unblock them from the Deco app to force re-association.

b) Flapping: another smart plug logged 35 disconnect/reconnect cycles in a single
   day (each ~10-20 seconds, recovers by itself).

c) Brief synchronized dropouts: several IoT clients drop at the same moment,
   5-7 times a day, for ~10-20 seconds, then auto-recover. My 2.4GHz channel is
   set to auto and I can see the Decos re-selecting channels when there is
   congestion — the timing makes me suspect the IoT radios don't handle the
   automatic channel switches gracefully.

Related: my cameras stay associated but get stuck to a far node and never roam
to the nearest satellite (ping goes from 2ms to 300-1600ms spikes). I have to
Block/Unblock them next to the correct unit to fix it. Battery sensors also
show association failures (signal reported as 0 until several retries).

3. Main/guest network: working perfectly. Wired clients and 5GHz/6GHz clients
have zero issues. The instability only affects the 2.4GHz IoT network.