Battle Net Communities - Party Invite Inconsistencies

So we are trying to convert our wow community to a battle-net community. The obvious perks being we can fit more members and members only need one invite spot for all their chars. Eliminating the need for secondary communities for overflow. The only issue we’ve run into, is that only SOME party invites work for the community chat. You get the invite option, only for some people, and sometimes even if you get it, it’s grey’ed out. I’ve tested with people on my battle-tag friends list…I get both clickable and greyed out invite option. Some I get nothing. Tested with different community rank didn’t seem to affect it. We had a couple people test and verify their privacy settings, and make sure invites from chat was not disabled under social. We even tried a work around by having them whisper people from the chat and see if you can invite directly from the whisper instead. Same issue, same people who were greyed out were still greyed out even when whispered. There has to be a rhyme or reason behind these inconsistencies for party invites.
And why hasn’t blizzard after all these years addressed such and easy to solve issue and streamlined this yet? It really shouldn’t be any different than the wow based communities in regards to invites. As long as they are online, in the same game, and on the same faction, invites shouldn’t be an issue. Has anyone determined the issue or found a viable work-around? Please share! Thank you!