I finally got my app working with my proxy server.   I saw the error when I logged in:

Your application is running with HTTPS mode set to http, but the request is an https request.

It tells me what to do so on my open project server I typed:

openproject config:set OPENPROJECT_HTTPS="true"

Then I typed:

openproject configure

It ran through a ton of things, the website came back I log in and bam same notification.  Not sure what else to check or look at to change this.  This was not working for a while as when using my proxy server I couldn't login (it would just hang) though going to the server this is deployed on's IP address directly all worked well.  Turns out I was missing this in my proxy servers config of the Virtual host:

RequestHeader set X_FORWARDED_PROTO 'https'

This allowed me to hit the url and login but then yes garnered that http/https error message I cannot get rid of.

Also hoping that will fix my last bug, in that logging in still does seem it 'hangs' but refreshing the browser after you successfully type the right username password combination and click login (while it looks hung up) loads you into the application (with that https request issue error).  So it is working-ish.

it is like a openproject configure erases my setting of the OPENPROJECT_HTTPS as I do a:

openproject config:get OPENPROJECT_HTTPS

and it returns true once I set it but once I run a configure it returns false again.