Maybe I found another issue after 7.5 update.
I have a Garmin Fenix 5, an Edge 1030 and Vector 3.
Above all with Garmin Fenix 5 and Edge 1030 at the end of the activity when they start to synchronize I have synchronization problem.
Many times I get message "Device is busy", or things like that.
And many times I need to restart Garmin Connect on iOS after one device sync, because the other one stops to sync.
I don't mention Vector 3 because if I pair them with Garmin Connect I have other problems while I'm riding with my phone.
During the day, while I wear only the Fenix 5, I have no issue, and everything works fine.