I have exactly the same problem. After a fresh install of the koa native on Ubuntu 20.04 according to this doc: https://openedx.atlassian.net/wiki/spaces/OpenOPS/pages/1969455764/Koa+Lilac+Native+Open+edX+platform+Ubuntu+20.04+64+bit+Installation
and am constantly routed to lms login in page or if I am logged in to the lms home.
The names resolution works for both domains also on the host machine.
What could have gone wrong?
Thanks and best regards