I've been having major connection, freeze, and disconnect problems in the last two weeks.
Happens few times in a month, especially after the maintanence. Usually try to avoid playing important tourneys on those days, as 95% it will be cancelled some point. Playing only sng, multisng micros, as this problem is still there, and can be really annoying after 6-8 hours play and in a good tourney positions.
I recognized the disconnections for few seconds, and it puts me sit out, happened several times in this week, it is something 'new', I experienced similar more than half year ago.
For the maintanance check out their soc media, tw, example, or here they have an official acr thread, they have the links there when and what they maintanance. so you can count on that.