Thanks HoTat2! My setup is in my signature and includes "...HR44-500, HR24-500 (x2), C51-100 and SlimLine stub mount with 3D2RBLNBR0-01."
As you also mentioned, my receivers too have been detecting the RB LNB I have (and they have been since it was installed by DIRECTV in 2016 as a replacement...