It’s cool if you work in 4/4. Not so much when you want to do any kind of odd time signature or polyrhythms. I use MIDI not USB as I would like to play out live with the AR, and the problem still occurs. The bug has been confirmed by Elektron, and they are able to reproduce it reliably with the project I sent them. It doesn’t make a difference if it’s getting clock from USB or MIDI. It’s always broken.
I’m glad to hear that it works for you in a “best situation” scenario, and with the help of a sync gen. But there are some for whom it does not work, and it doesn’t look like it’s getting fixed anytime soon, or even at all.