Yes I was thinking the same thing and just tried that apk file that you posted and it indeed works. Maybe I don’t know where to look but I can’t find that information for the packages on Fennec F-Droid | F-Droid - Free and Open Source Android App Repository anywhere.
I only found out by uploading both packages to Sixo Online APK Analyzer | sisik and checking the supported ABIs which indeed show “arm64-v8a” for the first package and “armeabi-v7a” for the other one. Anyway, the issues is resolved then.