Router "stealing" IoT devices from satellites

My system: NBK752 (router: NBR750 + 3 satellites: RBS750)

Distance between the router and the satellites: more than 35 feet

The satellites are connected to the router via a wired backhaul. and are evenly distributed through the house

I have 17 IoT devices connected, the most of them in the livingroom, very close to one of the satellites.

Periodically the router "steals" the IoT devices from the satellites (especially 2.4 gHz devices but also some 5 gHz ones), worsening the WiFi connection to the point that I have to disconnect the livingroom webcam, for example, and to reboot it to get it work again.

When I reboot all the IoT devices they immediately re-connect to the closest satellite for a while (days or hours).

Then the router takes over again...

Sometimes the IoT devices are "redistributed" to another (more or less) close satellite instead of being "captured" by the router.

The satellites are all perfectly working, no disconnections (UPS), latest firmware

I have seen in the discussions that there is not a permanent solution to force a satellite to connect to a certain device/IP address.

The most of the times they still function at a reduced speed (and for many of them speed is not a problem). But sometimes they simply get stuck and unreachable...

I cannot understand this operational logic...

Any ideas?

Thank you!