You're limping tons. Which probably works for you live, but it's often considered spewey online, and probably explains why you can only play 4-6 tables at once.

You probably give up on a lot of flops you miss, right? It's a fairly transparent strategy for anyone else running a HUD or paying attention, which becomes more important as you go up the limits.

I run like 18/14, and that's considered fairly loose. Many big multi-tablers play like 13/11. When you're that tight/aggressive, folding 87% of hands, it's easier to hand the table load.

I'd have to take a look at your positional stats, but you probably open limp far too much in MP with hands like Axs, SCs, KTo? Probably call too many preflop raises with QJo, AT,.. and such hands? That's suicide vs the TAG regs you find online.

I'd suggest posting your stats for review . There's a lot of guys around here who can give better advice than I on how to optimize your preflop game. Take a screenshot of your main stats, your detailed stats, your positional stats & anything else that might be relevant.