I'm trying to understand monitor distance matching for stretched resolutions.  Using CS:GO, I've inputted a stretched resolution (1024x768) with default FoV and tried to do a monitor distance - horizontal match with a standard 16:9 resolution but keeping the same horizontal FoV (90 degrees).  Why would the sensitivity be different?  Below is the calculator inputs.

 

It's different because the configured FOV in CSGO affects the sensitivity (i.e. changing FOV also changes 360 distance). If you tried the same thing with a game like Apex where FOV does not affect sensitivity you would get the same sensitivity:

 that makes sense, thanks.