Pondering this more, I think what I did was load single key aes via key admin, then went into the radio's control head menus and selected it as a global encryption key. Because as you said I couldn't assign it with RPM 1 and therefore also didn't assign it to any specific systems either.How did you assign the key as a Single-Key in RPM1 at the time? Key Admin only creates the AES/DES keys, the Key ID, Key Number etc. for the keyloader to load into the radio. RPM assigns the key as either a Single-Key AES or Single-Key DES key to the systems, channels or talkgroups in the mission plan.
I'm still not following how you were able to create a key in Key-Admin and then assign the key as a Single-Key AES or Single-Key DES key, as per the Single-Key feature, in RPM1, for the XG-100M.