I have figured out the issue. It’s due to my entitlements file using windows line endings (CRLF) and MacOS requiring unix line endings (LF) but not telling me. In my testing it only ever failed with a cryptic error “Code sign invalid” (we sign our app and notarize it perfectly fine).
This issue will be fixed in v0.7.0.
Once the new version is released, you will need to download the installer DMG again and install over the current app to get the fix.