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 - not if you have DV
mostly likely cause is line noise so
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
many thanks for your suggestions, but it seems to have cured it's self, I switched off overnight and switched on this morning and everything is back to normal. Once again many thanks
@lesterlad Hopefully your turning off the SH2 overnight was just a one-off for it isn't recommended to perform on/off too many times as this might confuse the system into believing you had an unstable connection. Hubs are best kept running.