I think I managed to get it working on my Pixel 9 Pro.
I uninstalled the app and during reinstallation, before logging in, I was able to change the theme from Light Theme to the 100 Years Theme.
After that, I logged in and the app seems to be working correctly.
However, if I change the theme back to Light Theme, the app crashes.
For now, I'll stick with the 100 Years Theme, which seems to work reliably.
I believe the issues started with the Android security update from May 5th, but it could also be due to an app update that happened in the following days.