@Thief-Garrett said in Installing along side preexisting intallation of wordpress on Apache2 (ubuntu):

So what I ended up doing was converting from Apache2 to Nginx and created a server entry for nodebb with SSL. I'm thinking it was primarily the SSL and lack of server block for nodebb causing the forums.example.com to redirect back to example.com

no need for a server block if they are running independently. I wouldn't recommend both on the same server for other reasons, but there is no reason for them to conflict.