F-Droid Build Status was updated to 5.6.4 and no one will get this update. Why? Well, the app is now built reproducibly so if you have it installed you need to uninstall it and then reinstall it. (Yes, we wish this switch to be easier to perform, but the UI is not there yet)
[…], from that point the app will be built by f-droid with their own digital signature.
This part of your comment is not quite true. One of the advantages of reproducible builds is that the app can be signed by the developer but fdroid can still verify that it has been built from the correct source code. You can check out the documentation here: https://f-droid.org/docs/Reproducible_Builds/
you’re right, thanks for letting me know
This means that F-Droid can verify that an app is 100% free software while still using the original developer’s APK signatures.
then I don’t understand it either why it can’t be updated directly