PowerStore: non-disruptive import fails to add host with not all host initiators present in a single external host

Non-disruptive (agent-based) import fails with the error message:

Addition of host failed due to not all host initiators present in a single external host. Check the initiator configuration and try again. (0xE0301003001D)

The installed host plugin reports all FC  or iSCSI initiators that are present or configured on the host to the PowerStore. During the host-plugin installation, transport type is set up so either only the iSCSI IQN or the FC WWPNs are reported.
PowerStore then validates if it can associate all initiators to the same host object.

If a host has two FC HBAs with two ports each, all 4 WWPNs are reported to PowerStore.

The host might only be using one initiator per HBA to connect to PowerStore. If the host object on PowerStore does not include all initiators of the hosts (even the unconnected ones), this error message is displayed.

Add all iSCSI, or all FC initiators to the host object even if they do not have any active connection to PowerStore.

Go to Compute, Host Information, (select the Host Group), select the Host, Initiators, Add Initiator
Initiators without an active session to PowerStore have to be added manually.

The host should have redundant connections to the Storage to allow IO - additional  initiators do not need to be connected.

Then re-try the import