Inconsistent wifi drops

From the UK, the issue isnt a drop in speed but that thw wifi just completely drops out from multiple devices (only have 6 connectedto the wifi) most of which in the same room as the router only a few feet away. I have tried speaking to our provider and they say our connection to the broadband is fine and they can detect 0 faults on their end so I have gone through every avenue they suggested of trying to reset and resolve the problem but it persists. We have had a new router and it still continues. It happens at random at any time of day, sometimes for just a moment sometimes for 20 minutes.

If anyone has any ideas as to what may resolve this id be extremely grateful.