I was using at Android 8.1 Oreo and also switched to One UI 1.0 (v9) last week.. Build nr. is currently: PPR1.180610.011.G960FXXU2CRLI .
If Pie is newer version, I think it is not updated on our region (Turkey) yet, becuase my S9 says it is updated for the latest release.
And Call Recording is still working
I dont understand why the hell this feature is not enabled in United Arab Emirates, it was not availbale neither on android 8 nor i updated to android 9 with one ui .. also not getting the reason to blocking this feature by samsung or region.
I decided to not update my phone since I bought it. Call recording still works for me, but the nagging messages to update the phone are super annoying.
I wonder why they have not disable the camera? It is "illegal" to record a voice, but voice and video is okay? Double standards :-)
According to me, Android One (9) is not as well as 8.. Because icons got bigger, settings menu got bigger, notifications got bigger and phone speed is extremely slower than before (at least in my phone!).. Samsung Gear icons lost and everytime I have to off/on bluetooth connection to reach Gear settings.. Sometimes, phone calls getting missed because trigger doesn't slide while phone is ringing..
So, if you have chance, you should wait a bit more to update (actually I didn't like the new version)..