jacob.salmela: Thank you very very much sir. Kudos, Same command worked on both my primary raspberry pi pihole server, and my little dedicated debian virtual machine pihole used as secondary dns server.
Both web interfaces for my primary pihole server and secondary now show:
Pi-hole Version v3.3 Web Interface Version v3.3 FTL Version v3.0
Again, thank you very much. I love the wonderful community this project has. Anyone perusing the help forums, I recommend donating to these guys. Great product, low resources, works great, especially combined with your favorite browser extensions, and the support is amazing.
Thank you again, and have a wonderful evening!