1 Step
Browse to your game files

2 Step
Found the executable named "mafiadefinitiveedition.exe"

3 Step
Right Click and select properties

4 Step
Go to compatibility and mark "Disable fullscreen optimizations" and "Run this program as an administrator" (For me worked with administrator you can try without administrator)

5 Step
Click apply and its done, enjoy :)

6 Step
Any question you can ask down here



You can also turn off Fullscreeen, window border and vsync and check if it get better