WiFi persistently disconnecting

[Becs1978]

WiFi constantly disconnecting every few minutes. I've followed all the guidance and it still continues. 
WiFi check says all ok but then disconnects again. 

I cannot even open my emails without it disconnecting. 

[Highlinder]

@Becs1978  black or white router from Sky?

[Becs1978]

Black router. 
WiFi connection when joined was 50 now not 24 

[Highlinder]

@Becs1978 Could you please post your router stats following the link below.
https://helpforum.sky.com/t5/Broadband/How-to-find-your-Sky-Broadband-router-stats/td-p/2855717#M101...