April 2020
You should have to use a warrior to do the bashing, and you use the action key and not actually attacking. If this is what you are doing, then it may be a glitch, otherwise you may just not be doing something right.
June 2021
There's another issue which can confuse things: if you don't bash the wall in the first room you encounter (on the left) and enter the right room, in the top left corner you'll see the bash icon, which moves around depending on where you stand but doesn't respond to anything. What you're seeing is the BASH icon from the first room, which goes right through the wall. Ignore it, go into the room to the left and bash the obvious wall and the 'ghost' icon will disappear in the 2nd (right) room.
August 2021
I had the same reaction! Off to break some doors, brb.