[SOLVED] CDJ900/Rekordbox lock function

Hi guys, new to the forum, I have generally managed to navigate my way around Rekordbox & the CDJ900 but I am stuck on this one.

I have Rekordbox 2.0.7 connected to a pair of CDJ900's with version 4.10 with the Pro DJ link via LAN, everything works fine except I would like to NOT be able to drag and drop a track to a CDJ that is playing or at least a box pops up asking am I sure?

I must be missing a setting somewhere?

Thanks for any help in advance.