rickspdx I’ve had success in setting up nginx this way and used the official documentation as a guide here:
Please let me know if you still need help – I can share my /etc/nginx/nginx.conf and /etc/nginx/conf.d/default.conf files.
I’ve had no issues in accessing either the main web interface, SoGo or Roundcube with nginx set up as reverse proxy, so it’s definitely possible.