mgmt_vdev@mgmt state UNKNOWN

Hi

what UNKOWN means in "ip a" command output :

20: mgmt_vdev@mgmt: mtu 1500 qdisc noqueue state UNKNOWN group default
link/ether {mac-address} brd ff:ff:ff:ff:ff:ff
inet {ip-address} scope global mgmt_vdev
valid_lft forever preferred_lft forever
inet6 {ip6-address} scope link
valid_lft forever preferred_lft forever

This is the management interface, interface is working fine, I point to it when accessing Unisphere & SSH.

I don't know if this is related to 2 log events dated as 6 weeks ago:

   4/15/2021 2:21    Port SPA A I/O Ethernet link is up

   4/15/2021 2:20    Port SPA A I/O Ethernet link is down

any explanation please?