I have a simple particle system with a collision plane that kills the particles on contact. I've turned ON Unborn and Dead under the Particle Render options, and Die on Hit under Physics. The particles are instanced objects. Every thing looks fine in all viewport modes including Rendered, but when I try to actually render a frame of killed particles that should appear stuck to the plane, they do not render - only the particles before collision. I've tried various combinations of killed and dead settings, and baking the simulation, but nothing works. I can only render the dead particles in viewport render.
The rendered particles are actually respawning after death on the emitter, but this only appears in the rendered image.
To trouble-shoot, I tried creating a simple particle scene in 2.79 and it performs and renders correctly. I saved the scene and opened it in 2.81, and it still rendered correctly. In 2.81 I re-created an identical particle system next to the imported 2.79 system, then ran them together, then rendered a frame. The 2.79 particles rendered correctly, but the 2.81 particles did not. I tried breaking the 2.79 system, and it seems the only way I could break it is to change the number of particles the emitter creates. Even if I assign the 2.81 particle setup to the 2.79 geometry, it still renders correctly.
So it appears there is a bug in the 2.81 particles, or the renderer related to particles.