Alright, this is very strange and concerning. Let's hope this isn't a bug that close to the end of the 48 hour grace period.
Are you sure you had the brush equipped when pressing the E button? You should see its model in front of you when equipped.
Press the "1" button on your keyboard to equip it. Your mouse's scrollwheel could potentially also work.
If nothing still happens, try approaching again from a different angle and coming even closer to the fireplace - could be some sort of 3D mesh issue.