RPi 3B limited to 7 Wifi clients
The RPi running in my car only allows a certain number of Wifi clients to connect. With every firmware update, so it seems, the maximum number is reduced. On our recent road trip only 7 Wifi devices could connect, while running kernel version 6.1.45. After a bit of searching, others have encountered the same problem.
Solution
Several solution directions are possible. One solution is to get an external Wifi adapter and not rely on the internal Wifi adapter. Another solution is to just switch to a minimal firmware for internal the Wifi chip. This can be done using the following command:
sudo update-alternatives --config cyfmac43455-sdio.bin
Select the cyfmac43455-sdio-minimal.bin firmware and then reboot. This should enable your RPi to support up to 19 clients.
Hostapd
It also makes sense to set max_num_sta=19 in the /etc/hostapd/hostapd.conf file. This will discourage a client from trying to associate with the AP when the maximum of 19 clients has been reached.
