Splitscreen camera glitch

hi i got issues with camera in splitscreen. it gliches by displying shadows wrong and some wierd colorful reflections. and its only on the second player camera. i think thats beacouse screen based reflection(its the only logical option, beacouse engine propably takes only frist player reflection to do the reflections) but when i change it to none or lumer it still gliches. some guy on yt said to delete config files after that but it just crashes the game. Does some know how to fix this or at least how to safetly delete or refresh config files?