I've updated my Mac to Mojave after getting the updated Osu! and my frames have been, well, bouncing? It goes from 120 down to 60 and back up. It's a rollercoaster ride honestly.
I play Osu! in a very simple way. No in-game interface, 100% bg dim, and I turn off skins and use only mine. I only have the frame counter on.
I've unchecked "Auto Detect GPU Info for Direct3D" and "Use 3D Boost (if available)" within Wineskin.
I'm not sure if Mojave itself causes the issues, or I've done something else. I hope someone can help me out.
Edit: I've temporarily "resolved" the issue by limiting my frames to 60 fps. I noticed that my ping has been going up and down between 9 and 30, which also causes my frames to do the same. I tested my internet speed, closed other applications, and ran Activity Monitor but it just seems that Osu! itself has an issue.