F-Droid 1.0-alpha0 does not show any available versions for an app if it is already installed but signed by a different key

• Device OS and version: Android 7.1.2
• Device model/manufacturer: Google Nexus 6P
• F-Droid version (in the About screen): 1.0-alpha0
• F-Droid privileged extension version (if installed): Not installed

The F-Droid client 1.0-alpha0 does not show any versions available for Privacy Browser. The metadata file correctly shows the available versions:

https://gitlab.com/fdroid/fdroiddata/blob/master/metadata/com.stoutner.privacybrowser.standard.txt

The F-Droid client 0.103.2 does show the last three versions as expected. F-Droid client 0.104 crashes when opening the Privacy Browser screen.