Hey, I'm using the steam deck too. ProtonDB (website) will be your best friend to see if anyone found any solutions for other games.

Long story short, there's no fix as far as I know / nobody's found one

true, i already checked protondb and submitted my report there but hopefully someone finds and posts a fix at some point, or who knows maybe a future proton update would end up fixing it coincidentally.

I don't have the black void but the water details (ripples and waves, etc) will blink in and out, depending on viewing angle.
Pretty sure I'm using the default Proton version (didn't make any changes in that regard, just installed and pressed play)