Question GTA 5 wierd FPS drop turning water quality up.

[Sanyo5]

So I've been playing GTA 5 for a couple days and I recognised that when I'm looking at some exact things my fps drops down from the 80s to 37-47. This only happens when I turn up the water quality from normal to high or very high. Also my gpu usage drops down from 80-90% to 40-50%.
PC: Vega 56
Ryzen 7 2700x
32 Gb DDR4 ram
1080p 75hz
What I tried:
Setting everything to the lowest only leaving the Water on very high : still drops a lot.
Editing radeon settings
Changing power options

 

[ElectrO_90]

I'd say that is strange, as you do have a very nice and powerful system.
Wish I could give you an answer.
I'm sure you have updated all drivers, but you may want to do a DDU on it first then reinstall...

 

[Sanyo5]

Thank you for taking your time and replying! I'll give it a try.

Edit: Unfortunately it did not work.