Official comment
Yup - if you don't see the blue dot in the middle of your jog in rekordbox, you're not in vinyl mode. To turn it on/off, hold the SHIFT button while pressing the SLIP button and that will toggle its status.
If you are having problems with latency in the response (you move the jog and it doesn't move the software for a half a second), please let me know and I'll send you instructions on correcting that.