Theme selection unavailable using web browser. OK with Android app

I rarely modify my custom theme, but recently I wanted to change it in browser and noticed it is no longer available. The theme selection pulldown shows properly in mobile app, but not in browser. I have cleared cache, use different browsers (Edge, Chrome), logged out/in. This has been working for years without an issue. Any clues?

Currently on latest versions:
Home Assistant OS 7.5

I have a themes.yaml file in my config directory, and the following lines in configuration.yaml:

  themes: !include themes.yaml

Had the same thing happen to me after the last update; just logged out - and of course again in - and the theme selection was back…

Thank you. I had resolved the issue with browser by login off and clearing cache. The Android app had the same issue while connected locally only. It took a cache wipe and uninstall/install to resolve it.