Wifi dropping out multiple times an hour

[#1]

Hello, 

Wondering if anyone can help. Our wifi with Plusnet has always been a bit hit and miss but in the last few weeks we've noticed it getting worse every day to the point that now the wifi is so weak even devices in the next room can't connect to it and the ones that can are dropping in and out every few minutes. 

I realise that there's likely to be much more pressure on the broadband over the last few weeks but that still wouldn't explain why its been getting significantly worse day by day. 

Any advice would be very much appreciated. 

[#2]

Been having the same problem. Was told my router not dumped cache in 41 days and I should reset. Did so but has just got worse. Miss plain broadband as ever since getting fibre been experiencing multiple problems across 4 different providers.