@MikeC_81 I thank you for the solution

dgVoodoo2 solves the problem for me perfectly

it works for me too

I changed several alternative settings without success

I have no VM.
Here is my DxDiag-Report :

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System Information
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Time of this report: 9/17/2019, 22:45:02
Machine name: ---
Machine Id: ---
Operating System: Windows 10 Pro 64-bit (10.0, Build 18362) (18362.19h1_release.190318-1202)
Language: German (Regional ...

Big thank you for your prompt response!

I have a PC, no Mac.
Here is my DxDiag-Report-File: [EDITED TO REMOVE FILE SITE WHICH DOESN'T SEEM TO BE VERY FRIENDLY...]

Hi,

I have a graphic bug with border hills, see screenshot: https://ibb.co/PzqDS10. All border of the hills look just like water.
I tried many different settings without success.
I have Win10, AMD Radeon RX 5700 (Softwareversion: 19.9.2), AMD Ryzen 7 2700, 16 GB RAM.

Can you please help me out?