I am having the same issue. I purchased the hybrid model that is ADS-B MLAT AIS. Great response from the Radarbox side, but the ShipXplorer side there has been zilch in communications or requests to activate my unit. It is one of the units with 2 IDs on the back, a PGANRBxxxxxx and a SRANSXxxxxxx. The manual says to go cliam it like the raspberry pi and enter the sharing key which is supposed to be those above, but it says key not found. I just dump more $$$ than I really should have to have no support or at least allow me to self-register.
Thanks in advance for any help that can be provided.