Brave browser on win10
Do all the cases consecutively
In GM/editing view: Hit F5 (clean slate)
Case 1 (expanded side pane): press s for measuring, use it, hit space bar, use laser, hit s use measure - no problem
Case 2: collapse side pane, hit s, use measuring, hit spacebar, use laser, hit s, use measure - no problem
Case 3: expand side pane, hit spacebar, laser works but spacebar also toggles side pane. Toggle until expanded
Case 4: hit s, use measuring, collapse side pane (tap mouse on pane) hit spacebar, laser works but toggles pane
In player view:
Case 1: F5 for a fresh start, this moves you to edit/GM mode,
hit s, use measuring, tap "View as player"in the pane, hit space bar, laser works but it toggles between GM and player view.
Now, in Player view run case 1-4 of GM/edit view and results for the cases will be the same.
I use s/measuring tool through all the cases, maybe there are other cases with other tools. My guess is that use of measuring involve tapping and that clears some state while the laser never gets the state cleared as the only action comes from moving the pointer. Just my cents.
Hope it helps. Else the bug sits on my side of the screen XD