Mattermost Websocket handshake fails when using apache as proxy

[XxLilBoPeepsxX]

Thanks for all the information, it is quite useful! Specifically, this part:

@Johnny99211

AH01144: No protocol handler was valid for the URL /api/v4/websocket (scheme 'ws'). If you are using a DSO version of mod_proxy, make sure the proxy submodules are included in the configuration using LoadModule.

Could you enable the module proxy_ajp and see if that works?