One of FortiSIEM automated HA follower node status is inactive

Hi ALL,

We have deployed three All-in-One supervisor nodes (S1, S2, S3) configured in automated HA. FortiSIEM version 7.3.2.  All nodes were active and in good health initially.

After about 20 days, one of the follower nodes (S2) went down and remained offline for approximately 7 days. When we brought this node back online, it appeared as inactive, and upon attempting to edit it, we received the message: "You need to delete this node."

My question is — to re-add this node, do I simply need to delete it and add it again after S3, keeping the existing Admin SSH public key and HA user SSH public key unchanged? Or is there any other recommended procedure to restore it?

Please advise.