Ive had a few times this hapening to me, inside the tower of the dead ive sometimes lost the ability to use buttons nr 1 and 2 (left and right clicks), nr 3 and nr 4 still work.

If i tab out of the game i can normaly use the mouse, so its only ocurring inside the game and to fix it im forced do exit the game and retart it, makes trying solo tower of the dead abit hard.

If i could get some help, it would be great, ty