I searched for my issue and topic similar to mine, and looked through the topics in this forum, checking out all the directv ones. Could not find anything. Apologies if this is somewhere else on the site, not trying to waste anyone's time. If it is link me to the post please.

I have 3 H21 receivers, stacked on top of each other, going to 3 displays. Id like to use one remote to control all three, if possible. I set the code for AV1 to 00002 and the code for AV2 to 00003, but when i go into the remote control > receiver mode it is only 'AV1 or AV2' not one or the other. I left the DTV symbol as 0001, so it controls the #1 unit, AV1 now controls the #2 unit, but #3 is also controlled by DTV symbol.

If it helps one unit came with a RC32 remote, but I think that is older model

Side note: All these links to the 'mega list' of codes are dead. Even ones I got from google searching