When I’ve been playing rush hour services the game freezes for like 5 seconds then the frame rate and gameplay is laggy playing the whole route, hope this helps to sort the problem out
It’s happening to me aswell, I am running on the Xbox Series X and also on PS5. None of the other rush hour routes aren’t effected just London to Brighton has all of the bugs, low frame rates and audio issues.
I also have this issue, laggy, frame rate dropped, my PS4 fans going like crazy too! Just for London Victoria rush hour routes. PS4 Pro too so should be working fine.