@Zanvetto
Hi,
The Tapo battery-powered cameras do not have the Auto Reboot or Schedule Reboot feature. For your feature request, you can vote and leave your comments on the thread "Auto-reboot for C425" for evaluation.
In your situation, when the camera is working, please go to its Device Settings > Device Info page, tap the Wi-Fi icon, and check the RSSI value. If the RSSI value is below -60 dBm, you can move the camera closer to the router to see if that helps.
You can also reboot your router after the camera disconnects and check if it restores. If so, rebooting your router is an alternative solution.
Best Regards