build reproducibility issues prevent reliable F-droid deployment

See the three build failures in https://monitor.f-droid.org/builds/build with error

> ERROR: Could not build app io.element.android.x: compared built binary to supplied reference binary but failed

I'm not able to further diagnose what is going on here. Is it possible to get access to the fdroid binary so someone could run diffoscope on it to get an idea of what is causing the differences between the binaries?