Haven’t checked the unlicensed version for some time but there’s no reason from 3.11 to 4.0… 4.01 that the app would behave differently.

You say the app and REAPER connected; Good.

How do you get REAPER to start playing?
Are you expecting X32 faders to move when you move faders in REAPER tracks? Because this is not what this app is about.