Minion got some settings at the top right UI corner where you can change the addon directory scan depth. Sometimes increasing this helps.
I can not speak for Unix, only for the Windows versions:
-Use 32bit version even on 64bit OS
-Start as admin to give it access to the user directory
-Allow the minion directory and elder scrolls online directory access (whitelist/exclusion list) in Antivirus/Firewalls
Maybe this helps you for Unix as wlel somehow
You could also try to stop minion, rename/delete the Minion.xml file!
Then go to your AddOns directory. Remove all addons (move them elsewhere).
Start minion, point to the addon dir.
Download a few addons new.
Close Minion.
Move/Copy the other addons into the AddOns directory again but do not overwrite any files.
Start minion again and check if it scans and updates properly now.