Caps lock was not on, and I still had the ability to jump. Testing in another browser, I noticed that caps lock being on stopped both shooting and jumping.
Reloading the save, I could still not shoot. Without changing anything, when I died, I returned to title and started a new game, and could shoot/jump. Reloading the previous save, that save still did not allow shooting.
So unfortunately not an input issue as this apparently corrupted my save.
Hopefully that might help a little :)