Hello! Please check out this topic: GPIO 7 reset pin busy - Raspberry Pi 3 - #2 by rodrigo.rolle
I haven’t updated my gateway to v4 yet, so I can’t say whether this solution still applies. Anyway, it used to work in versions like v3.3 and v3.4 (don’t forget to download the GatewayOS full image).
Another hint: after loggin in to your Raspberry Pi, type:
sudo tail -f /var/log/messages | grep chirpstack-concentratord
If you are seeing periodic reboot messages from Concentratord, the solution I presented in the link above should solve your issues.