Cluster stopped publishing metrics

This sounds like a temporary problem specific to these brokers, that may occur during maintenance. The best way to address issues like this is usually though a support ticket where we can access and discuss more specific details of you cluster. Please do raise a ticket for us with the details of your cluster, and we will take a look.

After 3 day the metrics are back.

It is worth noting that if you have very high partition counts, or are using smaller broker instance types, especially the t3 nodes which are intended primarily to development use, then there can be resource constraints that affect the publication of metrics like this. It is worth raising a support ticket to look into the specific details of the case, but the most common cause of these events is brokers that are small for their workload.