Hmmm, strange issue. As a temp way to play, you can use the middle mouse to drag-pan around. I'd suggest also clicking the 'reset hotkeys to default' button in the control settings if you have not already.
Send me your save file if you like. Some instructions on how to do so here: ...Read more
When you say nothing happened, you mean they continued to take damage? There's no visual success feedback for commands going through. Also, try typing that in all lower case.
An Ancient who owns the room will go there and activate it once and a while. When the beacon is active, it will light up void based blocks underground with a pink sparkle effect.