Cluster stuck in Starting status after upgrading to up53

Been running through stepped upgrades on a few of the clusters (some of them from up12 to up54 without issue)..

One cluster, however, is stuck (for reference, we'll refer to one host as "1" and the other host as "2"):
After getting both to up50, we upgraded "2" to up53
Then we moved all resources to the "2" up53 so "1" could be rebooted into up53
After "1" up53 came back up, the "2" up53 changed from "Degraded" to "Starting" and won't change
We tried even upgrading "1" up 53 to up54, and "2" up53 is still the Primary node and is still showing "Starting" and will NOT get out of that mode.

On "2" up53, status is "active" and replication state is "synced" but the persistent reservation sync is "inactive"

Is there a quick fix to get this running? If we try to Start the cluster on "1" up54 - it warns us that it will become active and that if the other node is still active, we'll have problems...

iSCSI is still working properly, but, we can't get the cluster to properly Start...

On "1" up54, if I try to Start the cluster (this is the secondary node right now):
Internal error occurred
Failover cluster could not perform requested operation (error code #HT24).
You may also start cluster services locally so all resources will be served from local node but please be aware it is not recommended.
Do you wish to start the cluster services locally?

And on "2" up53 (currently primary):
Cluster status: Starting

(Start button is grayed out, and I can't move resources to the "1" up54 server)

This could be a corrupted system volume on the array but we would need to check the log files, submit a support ticket so that we can check and see if the RAID Array is healthy.