How do I re establish wired WiFi connectivity in MacBook Pro [mid '15] OS 10.14.4?

I am using now a Linksys Velop router system (3 nodes, ). I can't establish a WiFi wired ethernet connection. Diagnostics tests do not show any malfunction.

Before I made this change three days ago, I did not have this problem even though I was using an old TimeCapsule. This device was failing and, since Apple discontinued the TimeCapsule line, I made this change.

Linksys support hasn't been able to resolve this issue.

Your assistance on this is appreciated.