All Virtual Standby's to Hyper-V fail with Access to the path is denied.
The Hyper-V server is on a HP StoreEasy Storage server. Which comes with ‘HP Storage Discovery Service’ enabled by default. HP Storage Discovery Service detects the .vhdx on the volumes and puts a lock on the file. The Exports fails due to the file lock.
Disable the 'HP Storage Discovery Service' in services.msc. The Exports should now complete successfully