I’ve found a few of the issues I’ve experienced with hair/fur have been fixed in the 5.4 update, and again with 5.5. Much of this was due to conflicts with static lights versus stationary lights versus moveable lights, as well as doing the opposite of what everyone suggested which was to disable “cast deep shadows” in light settings and disable “cast ray traced shadows” in the hair and light actors too.
The settings tweaked slightly between outdoor/natural light and generated light, but emissive textures in some instances were an affecting factor, while others not. Really inconsistent across the board - it was more things rendering on a lick and a prayer - and even then, my final product still had errors in despite several months of setbacks.
As I wrap up my project, I’ll be doing an in depth behind-the-scenes video breaking down not only the production elements that have gone into my project but also addressing the errors and how I fixed them. When that’s up, I’ll be sure to share my findings here in case anyone else may find them useful!