No FX on Output file but I hear the FX in my headphones

I thought this may have been from loading up a prior (Cubase 7 Pro) version which might have overlaid my Preferences file, but I found another thread here in the Forums, that says each Version of Cubase has it’s own Preferences file.
So I am to the drawing boards.
I recently loaded a project that was created when I had Cubase 7 Pro running, thinking I would need to do that in order for the project to be loaded into Cubase.
I’m not sure if I made any changes to the project while running it in Cubase7.
Then I opened it up in my current version, Cubase 10 Pro. I did make changes because I wanted to take advantage of the current plugins … e.g. Ozone 9.
My FX (Sir2 which I use on all my projects) are loaded on the output bus.
Any idea where to specifically look to find a solution to my problem?
Thx in advance for reading and hopefully replying. :pray: