I.e. I need not "sometimes" description, but rather "do #1, #2, #3 and you will get frozen buttons" or something like this.
Just like you describe that you had problems with buttons while do some streaming, I can confirm I do not have these problems even over tor. That's why I believe there should be a pattern breaking things. Or it is simply how end user internet connection works.
You play like 2 hands and you think "oh ok, it worked, i'm done" DO YOU NOT UNDERSTAND PEOPLE PLAY FOR DAYS. You'll never find your answer. Try playing on TOR for a few hours. I guarantee you'll start seeing massive problems.
1. play for a few hours against an opponent
2. where players are playing very aggressively and pressing a lot of buttons
3. it should be limit rather than NL, b/c limit invovled more clicking.
and you will get frozen buttons and problems, simple enough. No one is going to possibly provide you with exactly what you're looking for, or else those problems won't exist.
edit- what you are really asking for is worth like 500 btc's. you are pretty much asking "tell me how to fix this problem exactly" no one is going to be able to form an exact amount of steps and then take a screenshot to show u. and then when you replicate it, it will do the same. that is virtually impossible.