Enabling a custom saved theme causes an infinite duplication loop

Gets stuck in a loop of duplicating the theme css

1. Open the quickcss editor and type in anything, for example :root { --test: "hello"; }
2. Click Save and then "Save to Library"
3. Reload Fluxer
4. Go into Settings > Look & feel > Customize theme
5. Enable the "Custom CSS" theme in the "Themes" box
6. Keep opening and closing the quickcss editor and notice each time there are more entries

Note: "Sync theme across devices" in Settings > Look & feel (not in the quickcss editor) must be enabled. If enabled after the fact, you will need to re-toggle the theme again for it to start duplicating

canary build 649 (f01b7c0), Electron 41.2.2, Windows 11 10.0.26200 (x64), desktop canary 0.0.131, locale en-GB

Expected behaviour It saves and enables the theme like normal