Doorbell Wired WiFi channel 7 disconnects

Why is it when my Fritzbox 7590AX router changes its 2.4GHz channel to 7, the doorbell wired looses connection. After a few weeks of unplugging the doorbell a few times and a factory reset I then noticed the AX version of the XXXX changes its channels more often than the non AX XXXX (probably due to newer firmware) and this is when I discovered the disconnects happen on channel 7. It has good wifi strength and no problems with the other channels. I am in the UK.