An hour ago, halfway through a TF2 session, my TF2 started having this bug happen every time a player on the server I'm on spawns. What happens is when a player from any team spawns, the map's shading gets a tad bit darker for no reason for half a second then reverts back to normal. I'm also experiencing notable FPS drops when this happens.

You can notice it happen in the first second or so of this clip when the soldier spawns. The edges around corners appear to get a bit darker before going back to how they were. It's a lot more noticable in brighter areas.
https://clips.twitch.tv/PeppyDreamyEggplantDeIlluminati

Any help pls