Wifi random disconenct with Embedded AP (access point)
We had micro-pc (embedded) with Linux configured as Wifi Access Point (AP).
There were 2 problems
Too long Wifi Access Point (AP) startup, about 2 minutes, however login prompt appears in about 30 seconds
Unstable connection, clients randomly got connection loss, however AP looked to be alive
I've spent a lot of time looking for the reason. There was no troubleshooting for AP side.
The 1st problem was related to Network Manager (nmcli). Just disable or remove it from systemd config. Use hostapd instead.
The 2nd was a bit more complicated. Appeared, that some processes (BT daemons in my case) causes CPU 100% usage and pushed out hostapd for up to 10 seconds.
It is enough to make clients think that connection is lost. So, hostapd priority must be raised, all unnecessary and suspicious services must be removed from system.
This is also a reason for random disconencts from routers when they are attacked, meet packet storm or just some unknown or malformed packets. Disabling of unused services usually helps in this case.