Yeah, send a message to Arturia Support... This is one of the most annoying peculiarities. Osc 1 should be able to get fine tune offset. I'm constantly running into this and scratching my head on why its like this. Being able to fine tune each oscillator should be a given.
Also, being able to set each oscillator footing/octave in the menu would be very helpful. There's some basic sound design issues that need to be addressed... There are workarounds for these, but they really should just be addressed in a firmware update.