We reviewed some of the previous cases where it can be a config issue where we have member win on transfer from On-Prem to HUB and again member win from HUB to member. This topology can cause a circular conflict resolution. The recommendation was to configure between Hub -> member, the Hub win is what the correct way.
But please do this after you check with Support as they need to check your Azure Sync topology and run sync health checker. Please raise the ticket and please share the ticket number and we will try to get traction for the same.