Problem associating my new LHG 5 to the Old mANTBox

Good day everyone.
I got a new LHG 5 device for a client
And after all config, it’s not associating with my mANTBOX 19S wich I have been using for more than 2 years now.
I am running 20ghz channel on all my devices but only this new LHG 5 is not associating.

The only difference I noticed is that the LHG 5 has
(…/…/r2) at the end of it’s serial number. Pls does the “r2” means “Release 2” ?
Other LHG 5 that I have gotten has no “r2” at the end of their serial numbers.

Thanks.