Seems to have been fixed.
Can't move in Daily game.
Not fixed. Now it's happening to me. If I click and drag the piece to a square with the mouse without letting go of the mouse button, fine, but if I click the piece, and then click the destination square, it resets the piece back to the starting square, unless my destination click is insanely brief. If I hold the mouse button down for even a 20th of a second it seems, the piece reverts back to it's starting square from before the move attempt as soon as I let go the mouse button.
Can't move in Daily game: https://www.chess.com/game/daily/709597515
The confirmation button flashes on then disappears and the pieces are reset. Tried in Edge and Firefox.