FPS Issue

[dudebuster]

My game is capped at 144 and I can't change it to higher than that, not even from my PC settings. It only works if I change it to below 144.

In some places, like the dam, main hangar and now the concentrator in ZOC, the FPS suddenly drops to 120 or below and then goes back up, this all happens within a second. It makes the game seen laggy and it's super annoying to try to explore with that. It doesn't help if I cap it below 144. Any advice?