Have you checked the Disptach Console/DSE Session on the Node?

I currently only v15.5 available, but assume it is the same setup

We have fixed this.

Under  Dispatch Console Session that node was inactive.

But we are not sure how this one node got deactivated. 

Agree with Bjørn… another location though it is the same setting in is in the session definition such as seen below.  Both the setting mentioned above and this configure the same setting.

Thank you @bskallerud  & @Phil Seifert for your quick response and help.

I appreciate your help & very quick response