Polyrhythm not working on patterns longer than 16 steps?!

I was playing with the polyrhythm feature and it is fun… until I moved away from the standard 16-step pattern. Then it won’t really work as I’d expect it to.
For example: I want a drum sound (clave) to be played on step 3 and 6 and its length has to be 7 steps. It works perfectly when in 16 steps mode, but as soon as I double the steps, the polyrhythm gets deactivated somehow. Although my clave is still set to play on 3 and 6 and the last step is “7”, the clave will go through all the 32 steps…

As long as I’m not missing anything, I’d say this is a bug.
Can anyone help me understand?