Having issues getting websockets to work behind apache

We use Apache httpd on the front end, handling https/cert stuff and then using AJP to proxy to Tomcat. Fairly common setup. However, with 4.10.x it seems that spring websockets are being used by Emerse, and we have not been able to figure out the magic configuration to get this working with the Apache front end.
So, if we go to http://ourserver:8080/emerse, all is good, but going to https://ourserver/emerse will fail when we try to “Highlight Documents”. Any pointers on how to resolve this? I assume others are running Tomcat behind a proxy as we are.

This worked for us: https://stackoverflow.com/questions/25644487/httpd-returning-503-service-unavailable-with-mod-proxy-for-tomcat-8/28201422