We have feature services copied to AGOL from Portal through distributed collaboration. In AGOL these services are then shared with our Hub initiative. Sometimes the sharing gets reset (so services no long show up on Hub) and I'm trying to figure out the cause. We rebooted our enterprise server to see if that caused a reset but it didn't. Sometimes the distributed collaboration sync fails due to one feature service. When one item fails to sync could that cause the sharing for all the items to be reset?
@FPGIS_FrancescaRohrdid you ever find a cause or solution for this issue. I have just started trying to use distributed collaborations and I am running into this same issue. A service that has been shared with the public will eventually be set back to private on its own.
Unfortunately, I do not remember how that was fixed. While our program does rely on distributed collaboration as a way to share our data from AGOL, rather than from our on-premises Enterprise, we have found that it needs close watching as issues do arise. Good luck with yours.