Frame loss while playing on servers

I’m playing rn in a server that’s getting 100+ people a night im from Europe and through the day for me the city has like 30/40 players

Im getting 90 frames while the city is like this but for some reason later on when more people join it goes down to like 50 frames

I have played in other city’s with 100+ people on and get 100+ frames what can I do to fix this issue