Explosive Shot suddenly stopped detonating grenades.

I logged in last Sunday, crashing twice in the process, and found that my Tactician Mercenary's Explosive Shot has stopped detonating grenades and igniting oil. Nothing changed between then and the last time I played.

It looks fine visually and does set enemies on fire. It's like the 'detonator' tag got messed up.

I've tried the following in an attempt to get it working again, with no success:
- Removed support gems.
- Replaced skill gem.
- Unequipped and re-equipped the crossbow.
- Replaced the crossbow with a previously-used crossbow.
- Restarting PoE2.
- Verifying game files.

This is my only character so this kinda sucks.