Fix cum particles
In the last few FVNE versions, cum particles are invisible when viewed from certain angles. I have not figured out what exactly causes it, but it's easily reproducible by dropping a character into an interaction, making them cum repeatedly, and orbiting the camera around at various angles until you see the bad behavior.
Developer response
Cum will be remade entirely for HDRP, so this will be fixed along with that.
With build version 15.04.2026 we fixed an issue where cum wasn't visible from certain angles and tweaked cum particle material to produce better visibility.
18.04.26
-Blacky
Most likely a bug related towards either BIRP or Unity 6.
Since we move to HDRP anyway, we'll investigate on this as soon as we have a beta build. HDRP might automatically fix it.
You can try using the -force-d3d11 flag and see if it makes it better.