It is a mouse error or you're going crazy, since I've never noticed anyone else experiencing something like this.
I advise you not to drag the pieces, but to make your moves by clicking the piece and then the target square. That way such things won't happen.
Hi, am I the only person this happens to!
Any number of times and often at crucial moments I move a pawn forward 2 squares but he only moves one!!!
It is NOT a mouse error, and I am not crazy; I believe it is a fault in the site.
Anyone else out there experiencing this?
Yes "the site" (some mischievous artificial intelligence no doubt) waits for those crucial moments and suddenly limits your pawns to 1 move forward. That sounds completely reasonable.
... that or maybe... just maybe (and I know this sounds crazy) but because it's a crucial moment you're going to fast or are nervous and it's human error.
Very similar symptom for me, but only on opening move and only whilst using my phone. So far this is the only post I've found seemingly related. It's been a long time since I played anything here, but trying today, using my phone on Chess.com (Firefox browser), every single time I try the opening move, tapping any pawn (no drag, and no second tap) automatically moves it only one space forward, usually instantly ruining my intended opening. For the rest of the game, pawns move normally though. It also doesn't happen on Firefox browser for PC and I've yet to find any setting that would cause this.
Anybody know what could be the problem and be willing to help a befuddled user?
Well, I didn't find an explanation or solution, but, with a little troubleshooting experimentation (and a lotta resigned games 
), I at least found a consistent workaround.
On the opening move (still using Firefox browser on Android phone), if I first tap any empty space on the board prior to tapping a pawn, I am then able to move it one or two spaces without issue. It seems the "board" is somehow not "active" upon initiation of the game and simply tapping to select it then allows normal pawn selection and movement, whereas trying to select a pawn on an "inactive" board somehow automatically moves it forward just one space.
It's an extreme longshot, but this could perhaps explain JoeMoran7's mysterious problem. Perhaps something done during a game can deactiveate the board and, by random chance, if the next move starts by selecting an unmoved pawn, it would mysteriously just move one space forward.
Ya never know. Bugs turn up now an again 
hi
Hi, am I the only person this happens to!
Any number of times and often at crucial moments I move a pawn forward 2 squares but he only moves one!!!
It is NOT a mouse error, and I am not crazy; I believe it is a fault in the site.
Anyone else out there experiencing this?