You did not mention how you connected RX and Laptop. Is it directly on via router, switch. For me it never worked with direct connection, but via router - no problem at all. RX has to get dynamic IP on the same range as your laptop and they will see each other. Also, make sure you have ports opened. If it is Windows system on your laptop, when you installed rekordbox it probably asked you about a connection to private and public networks - just allow all and you should be good to go. I am not Mac user, so can't suggest anything on that matter.
As for the disk, i have 2TB disk, too, and it works just fine.
You should format it like it is mentioned on some of the official help forum topics (HP formatter). Works fine. Takes a long time (and you should format disk 2 times), but is is worth to wait. I had no problems whatsoever after that.
Windows 10, latest RX 1.60 drivers, latest rekordbox.