New Nexus admin : Why does create tag and Upload to repo fail?

Please forgive me being noisy in the present. This has devolved into a poignant problem. My apologies in advance if I have missed something

SetUp: Nexus 3 pro running on 2 redhat 8 servers. Newly installed.

Historical – N1 has jenkins and Nexus 3 on it. A trial application was able to successfully create a tag as well as upload a test artifact into Nexus repo on N1. ( Short haul - one machine only )The code does indeed work in jenkins.

Application Suite: the 2 redhats n1 and n2 are to be homes for nexus repos. My script that was running on N1 is migrating on over to production, first as a code on, later perhaps it will become a library job. My test script has been migrated onto production. Nexus platform plugin has been installed on all jenkins servers at this time. Configuration data seems ok.

Problem: I ironed out any glitches/inconsistencies on my code side. Checked plugins and config data. So I pop my program into a simple pipeline and ---- Create tag was showing valid data being sent to it — “Failing Build due to: Create tag was unable to complete”

Further down the output, I see an exception message stack from the repo manager Exception for a response Message. Message suggests unserializable expression.

Okay – as problems be. I am considering using a Curl command in order to feed on over a block of data for the tag. If it does not work, I will look along the lines of system to try to find out the why. If this does work, then it is a case of the jenkins on the remote box needing some care to be properly connected to the nexii ( individual Nexus instance on the nZ ).

Has curl worked for you folks? Any suggestions on what I might try?

Thank you for your support.