Are your devices connected with just wifi or is it happening to Ethernet connections?
which hub do you have? Does the lights on the hub change colour?
in order for the forum members to help please can you post the stats from your router (if hub enter 192.168.1.254 in your browser) and if HH5 then go to troubleshooting then helpdesk and if HH6/SH2 then advanced settings then technical log information .
Have you tried the quiet line test? - dial 17070 option 2 - should hear nothing - best done with a corded phone. if cordless phone you may hear a 'dull hum' which is normal
enter your phone number and post results remember to delete number https://www.broadbandchecker.btwholesale.com/#/ADSL
Someone may then be able to offer help/assistance/suggestions to your problem
Have you turned off smart setup?
have you split the wireless networks as that often helps. Also select the wifi channels manually instead of using auto
These should help