Hopper and Joey use IR remote address 1, period. There is no pairing, no stealing of codes, no uploading of codes from the Hopper/Joey, no nothing. That's not how the IR remotes work. So the codes from the 21.0 will work fine regardless of any futile pairing attempt, provided the remote is set to address 1 by installing the key in position 1. Pairing only comes into play with UHF remotes 32.0 and 40.0. Pairing isn't related to IR in any way whatsoever. I will reiterate that the Hopper/Joey codes are no different than your 622 address 1 codes. If your 622 happened to be set to a different address, then you will have problems. That's entirely possible, because I have no idea how your installer originally set up your 622.
As a test, set the 21.0 remote to address 1 and do not attempt any pairing. It should work all your Hoppers and Joeys provided they truly have IR enabled and you aren't getting any IR interference from your TV screen or strong ambient lighting. Until you get the Hopper/Joey to respond to your 21.0 remote, there's no point in going any further. Because that much should definitely work.
I'll be happy to post all the Hopper/Joey codes in pronto hex if that is any help to you.