Collabora not working behind sophos utm web application firewall (reverse proxy)

I have set up a nextcloud VM with collabora using the scripts from . So far everything has been working perfectly except for collabora when accessed from outside of my network. I have the sophos utm set up using the utm’s web application firewall to add an extra layer of security. I configured my skip lists for rules that were causing false positives and confirmed everything in nextcloud was working properly even outside of my network, however, when I click a document to open it I just get a blank gray screen like collabora starts to load but then never finishes. I do not see anything in the utm logs that appear to show anything being blocked. If I try to use collabora from inside my network or if I change the utm to just forward the port instead of using the proxy/web application firewall I do not have any issues. Even if I leave the web application firewall enabled and do not use a firewall profile it still does not work.

Is there something I may need to change in the web server or VMs configuration? Any suggestions would be greatly appreciated.