I have this issue if that is what you mean, during the evening the SNR drops from the day and if synced during the day the connection grinds to a halt but does not resync.
Hopefully Sky will set a Max stable rate, or basically I leave at the evening sync rate.
mine always needs a reboot if synched at a higher rate during the day sunday evening being the worst time
just had another reboot, i find if its rebooted at a peak time no further reboots are required and the noise margin stays above 5...the other night it ground to a halt and the noise margin was 2.5...not complaining at �5 a month...but auto reboot of the router would be handy