ML is available but not enabled

Please refer to:

In that post you should see that:

xpack.ml.enable should be true on all nodes as it is required for the nodes to talk 'ml' to each other. node.ml should only be set on the node you want the machine learning jobs to run on.

Seems like you should set xpack.ml.enable to be true on all nodes and then only set node.ml to be true on db5