The new VRChat update has broken the On-ParticleCollision trigger for SDK2. I've checked to make sure nothing was changed within my collision matrix for the world and made sure that I did not have "Send Collision Message" disabled. My bullet hell world, Sorano, is a prime example for this trigger not working.

To replicate the issue, if you join the world, pick up her threat, and start the raid? Her projectile attacks do NOT kill players. Using the guns to break the shields surrounding crystals and the crystals themselves when the raid starts as well do not register either.

Particles do collide however, the ability to send a collision message seems to be the primary issue.