I don’t use it often, but I recently tried using the iOS SmartThings app and noticed that the touchpad remote didn’t work properly against the new Plex app.
I’m not sure exactly what “should” work, but a light tap on the touchpad didn’t seem to register, and I could use my finger to drag the cursor around the screen but then it wouldn’t select what I stopped on. I do recall this working on the previous version.
Works when I tried on my device. You have to hold down the touchpad to act as the “OK”, rather than tapping it. I don’t believe I have the ability to control how that remote works, since we don’t support mouse input.