I’m pretty sure this started with 3.5 but I’m not entirely sure. Basically, Renoise’s renderer occasionally loses its mind under macOS 15. In this example you can see that hovering over different sections causes them to flicker. (This is with Metal rendering turned off.)
I’ve had much worse than this, where Cmd-tabbing into Renoise caused it to go completely white until I started mousing over stuff or repeatedly Cmd-tabbing/unhiding the window until it sorted itself out. Initially I chalked it up to my graphics card being wonky but I’m starting to think it’s a bug.
This seems to be triggered by fullscreening other apps that use the GPU while Renoise is running—but again, I’m not sure.