Certain devices repeatedly drop wifi and cannot reconnect without a restart

[justwantwifi]

Hi, I've been having a recurring problem in my household where the wifi works well except for on two devices (the same each time). These devices disconnect every few days and refuse to reconnect - I have tried forgetting and then rejoining the network, but then see a message that the network key is not correct, despite it definitely being the correct password. The only thing which helps is to restart the router, at which point it then accepts the password and lets them rejoin.

Does anyone have any suggestions why this might be, and what I could do to prevent it? 

Thank you!

[imjolly]

unless you have the SH2 have you split the networks?

https://www.bt.com/help/broadband/fix-a-problem/broadband-and-wi-fi/i-want-to-improve-my-wi-fi/how-d...

have you changed lease time from 1 day to 21 days

have you tried changing wireless channels by using a wifi analyser on phone to see surrounding networks and choose a less congestion channel