Marcel,
I've done some further investigation on this issue. Inside the 8-pin device, HOLD is left floating. I took the potentiometers off of the DRV120EVM and used the 14-pin device like the 8-pin device by floating the HOLD pin. I then grounded the OSC and PEAK pins, so they were set to default settings. The interesting thing I found was that a low-resistance, low-inductance coil performed as expected, but the high-resistance, high-inductance coil (one that is similar to yours) had issues. My scope shots are below.
From what I observed on the bench, I believe that if you use the 14-pin device and do NOT float the hold pin, you should get reliable performance.
Thank you for bringing this issue to our attention. We will need time to do further investigation here and improve our products and documentation.
Let me know if you have any other questions.
20-mH, 11-Ohm coil
600-mH, 660-Ohm coil