Today my customer configured some VLAN’s on a Hyper-V cluster in their DMZ.
They did this by using the “HP Network Configuration Utility” something like the following:

After this they’ve created a virtual switches for each VLAN. Not a unusual configuration and one I’ve seen in multiple environments.

And now comes the little gotcha…
When a virtual switch is created, by default the “Allow management operating system to share this network adapter” setting is enabled.

So, in order to solve the issue that the CSVs are suddenly only accessible through a single host, disable that setting for each virtual switch which is intended for VM traffic.