I hope you a had a session,where you destroy a small portion of your roll because those times grinding 60 buy ins over 90k hands was a big grind.

I think Stacks might have answer it for you.Winrate dropping due to the amount of tables you just added?I think that just might be it.I dont think variance is in your game for now,but your winrate(amount of tables) and probably tilt control.

I grinded out 20 buy ins over 20k hands on 6max 2-3 weeks ago on 25NL,just to lose that the same amount due to TILT and adding 2 extra tables(i play 6 tables max on 6max).So for the past week or so,i have been just controlling my emotion and stability.and yea,im back beating 25NL 6max for 5tpbb/100.

I would suggest dropping some tables,and go from there probably.