I can't make it work

The result is same with what's on https://forum.xda-developers.com/showpost.php?p=81138753&postcount=50 I'm not with MicroG nor LineageOS (or any custom ROM) though, just official.

More specific:

• The notification for sync repo in background sometime just hang there without ability to clear it, except I force close the app or restart the device.
• The list will be empty whatever I chose/done in Repository settings. If I hit manually the "Syncing Repositories" blue button, these are the messages;

1. "F-Droid - Downloaded" then followed by,
2. "F-Droid - Sync failed" and last,
3. "All repositories synced" (weird).

My system:

• Samsung SM-A300FU. Yes, it's an old and fail garbage from Samsung but it still work.
• Android 6.0.1.
• Aurora Droid 1.0.3~1.0.4

Thank you.

Edited: Add Aurora Droid version I ever use/test.