@Trollby 

If some devices work fine, then at least the router was not affected by the power outage.

What you could try to do is to forget the wireless network on both mobile devices and reconnect.

Aside from the router, connect those devices to other wireless networks to see if the drops still happen to see if the problem follows the mobile devices.

5GHz will not be able to reach as far compared to the 2.4GHz so if both devices have been on the 5GHz, switch to 2.4GHz.

@Tony 

Having the repeated dropping problem with my Moto G5+ also.  the C2300 drops the phone about every minute and reconnects right away.  problematic when playing games, streaming ...

any insights?