This was part of a game analysis feature added a while back; I'm not exactly sure what its purpose served, but when you hold down a letter key on your keyboard while clicking a square, it generates an icon on that square. For example a smiley face, or a "blunder" symbol, or a gold star. If you'd like to use this feature in analysis, click one of your squares while holding down the E-key, and it will give you a small window of all the icons available and the key-shortcuts that put them on your chessboard. I find that this feature helps when analyzing my games sometimes, just to keep track of all the different parts of the game going through my head, but it's mostly useless in game and it can be very annoying while playing live.
Anyway, this should only be happening when you click your pieces while holding down a key, so check your keyboard for any broken keys or keys that get stuck sometimes, specificially your 0 (zero) -key, because that's the key that brings up the smiley face emoji. Does that key ever stick down after you press it, or does it feel like there's something underneath it? If you're serious about the issue and do think there might be something stuck down there, I might suggest cleaning below the keycap. However, this is likely not the cause of the problem. If you're not experiencing any issues with your computer keyboard, which is most likely, then I'm not sure how to help you. This has never happened to me before, it's probably a problem with the website itself, so you could try bringing it up here:
https://www.chess.com/club/help-and-support/ (Chess.com's Official Help and Support Club) and if you don't get any worthwhile answers, here:
https://support.chess.com/ (Chess.com's Support Page) where you can contact the staff directly.
Very sorry about the length of my answer, hope I didn't have you reading too long.
Let me know if this helps!
This has happened to me multiple times - Randomly throughout a game I will try to move a piece and a smiley face emoji will appear on the square; and I am unable to move any pieces. Just smiley faces on any square i click.
It happened to one of my opponents in a game, i found out in the chat. So its not just me. What on earth?!?!? Somebody please help.
If i go into settings and turn on DMG board, save, then go back and turn it off, save again, the issue is resolved (I discovered by trial and error) but this is ridiculous obviously, lol.