Moved from onlook-dev#2078 as per @Kitenite 's request. Not tested on current version because I can no longer find a download link on the web site.

Describe the bug

$ ./Onlook-x86_64.AppImage

(process:477913): Gtk-ERROR **: 09:21:13.411: GTK 2/3 symbols detected. Using GTK 2/3 and GTK 4 in the same process is not supported
Trace/breakpoint trap (core dumped)

Haven't investigated in depth but here's the same issue in logseq. It doesn't reference the fixing commit explicitly but looking at the date I think it's this one.