Line sync decrease

[#1]

Hi all, I've been getting solid 70-72mbps IP profile since G.INP was enabled last July for me. Using an unlocked HG612 + ASUS RT-AC68U setup. Accidentally turned off my HG612 modem the other day and turned it back on straight away. Resynced much lower and as a result my sync dropped to 68mb (from 72-73) and IP profile dropped to 66mb (from 70-72).
Is there anything I can do about this? Have rebooted the modem again after 24 hours only to sync at the same 68mb speed.
Attached PDFs containing stats from HG612:
19/03/16 - Router working fine with normal sync
20/03/16 - Post-turning on router after accidental reset
21/03/16 - Waiting 24h for another reset
Worth raising a fault over? Thanks in advance 

[#2]

Disconnect the modem for 30 minutes between the time of 10am-12pm. Rebooting the modem in the evening/night/early morning isn't ideal due to more electronic devices powered on and higher atmospheric noise levels. The 30 minutes down time is so that DLM does not detect the power down as a fault which can lead to DLM slowing your connection down to compensate for something that hasn't occurred.
If your speeds remain the same, a possibility is due to an increase of VDSL2 uptake that can lead to crosstalk, it can be countered with using Vectoring, of which hasn't been implemented yet.

[#3]

Hello,
That's not a massive loss in speed, turning it off and on quickly like you stated will have caused DLM to possibly set interleaving on.
You are best to leave modem connected and it should return, may take a few days providing line is stable.