When this problem happens, it means you either have an even number of nodes in the cluster like 2 or 6 or 8.
The way I solved this issue is by creating another promox node on a different server. But then you cannot join
because the cluster is offline.
So, booted up all the nodes/servers that I never used but they had joined the cluster but where offline. When I booted them up, some of the servers joined the cluster on for some reason the cluster started working again with few nodes that joined.
But at that point, I had done some damage to the nodes that hosted Nas and San storage. These nodes
where not able to join the cluster so I ended up removing these nodes from the cluster and all started working.