Full fibre with wifi dropping

[GSherd]

Ive been having issues since january with seevice dropping. Moved to full fibe and getting around 500 mbps into house, however, oftem in room nect to hub im dropping (off teams calls) tv glitching and kids gaming glitching. Had multiple engineers out and cant seem to resolve/find issue. 
Mbps in rooms can drop to 39/40 when run fast.com . Not always, very intermittent! 
please help!!

[jamesn123]

@GSherd 

This sounds like just a poor WiFi connection. Have you tried boosters?

[GSherd]

Yes, we've had boosters, resets and all sorts. No idea what is causing the issue. As modern house and no issues until January!