So in case anyone is trying to figure this out, you have to:
Rebuild from new
Download 6.9.3 from GitHub--do NOT use the Zomboid repo
Download your client keys and login from ExpressVPN
All will work then.
Gotta give it: those Zomboid guys are cryptic, but they do answer your question. 
So what IS the 'moving forward' solution here? I don't mind having to work/rework things from time to time, but it seems like ExpressVPN and LibrElec like incompatibility more than compatibility.
Should I switch VPNs? Switch to regular Raspbian?
See previous page/the posts directly before yours, you need 6.9.3, which you'll need to get from github
Negative--'dependency not resolved' error. Tried installing outright, tried removing previous version and installing 6.9.3, same error.
So should I roll back LibreElec and try 6.9.3? Or will I have to rebuild completely and hope 6.9.3 works on a raw unit?
EDIT: You have to start from a raw build.
zomboided Been trying to install OpenVPN onto a 10.0.0 LE Pi 4GB. It completes the repo successfully, but there is only a Video add-on for "Kids TV". No Services option at all.
Just did this successfully a couple weeks ago, and am following the same procedure. THAT system (that was working) is now not connecting to my VPN. FWIW, my VPN connects just fine via PC, but the Pi version seems to be having serious issues.
