I’ve found this too, although the problem occurs before even trying to sync to another app. There seems to be some kind of internal timing problem when using loop markers.
To illustrate, try setting the BPM to 120 and setting a one bar loop with the metronome on. If you run it against a stopwatch you’d expect the tick of the metronome to occur exactly every 0.5 seconds (so two ticks per second). After just a few loops the tempo will start to drift. Quite noticeably too. So much so that it’s impossible to use loops in Cubasis and sync them to anything else.
Like you, I’ve tried this on several devices and all have the same problem.
I’m surprised no-one else has reported this. Seems like quite a big deal to have such an important thing broken.
I’m really hoping they fix this too as it’s useless to me without being able to sync loops in Cubasis to Ableton Live.