unity – Flicking issue on Linux build only

I’m about to release my second game in the next couple of days. A tester now reported that he has a flicker issue running the game on Linux. It´s related to objects like the water, the hex tiles and object on top of the hextiles.
In Windows everything works like a charm but on Linux all the graphics flicker. I think it´s a graphical problem related to the Z-buffer since the flicking objects all have the same world space position. I´m using the URP and created all the shader by Unity Shader Graph.
Does anyone know how I can fix the issue?

This it how it looks:
Flickering issue on Linux (Ubuntu)

Any kind of help is appreciated!
Thanks in advance!