Weird graphic glitch on Quest 3 / 3s

I encountered this graphic glitch on Quest 3 /3s ... but the same app works flawlessly on Quest 1 and 2!

 It seems to appear on translucent materials only. I tried all the possibile fixes (custom depth, disable fog, disable depth fade, ...) but nothing worked so far. Suggestions? Ideas?

It seems to happen in screen space and not everywhere (that "water" material and randomly around opaque meshes againts tranlucent ones and/or translucent againts opaque. Built with UE4.25 (Oculus branch) back in 2021 - and I won't refactor that on 4.26+ / 5.x ;)