Ok -- I don't know what OP did -- but this is what i ended up doing...
Situation: Currently all the kids (3DS, 16, 13, 8) have plans managed by me. DH has his own Disney account but doesn't use it (i control it). The kids have new MB+. Older two have their own phones, youngest will use mine.
For DS16 and DS13 -- on their phones -- I downloaded the Play app and MDE.
1. I logged on to MDE on their phone with my account. This probably could have been done on my own phone, but I wanted to make sure their MB+ was paired on their phone (I really dont know if this is necessary).
2. From the threeline hamburger on the bottom right, chose MagicBands and more. Since their profiles were all managed by me -- i could see them. Paired the respective DS MB+ to their profile. I had to do the weird tilting thing to get it to pair.
3. Updated their MB+.
4. Went to Play Disney app -- I had to create a new account -- I thought because they are still minors -- there would be a way to still have it managed by me, but no. You have to enter their birthdate (this became important for the DS8 who is too young to have a truly separate account), and then setup a disney account (email and password. I did this and picked something I would remember and not rely on the kids).
5. Then in the play disney app, picked one the games that requires a MB+ -- and clicked pair (doing this from memory so exact wording is probably something different) -- this then pushes you back to the MDE. I log off of my account in their MDE, log in as their new account.
6. Once I'm in their new MDE account, again, go to the three line hamburger on the far right, but scroll down till you get to "My Profile"
7. Under "My Profile", scroll down to "Show my linking code"
8. Then - back on my own phone with my own MDE account logged in, I go and selected "Family and Friends List" -- where I see DS16/13. They should have a greyish QR code type icon -- select that and scan their linking code into your account.
9. It will ask if you want to Merge -- check the info and hit yes.
10. From here -- they should have their Play Disney app linked to their magic bands (instead of saying link MB+ it will just say "Start Quest" or something for those games.
11. I recall I either had to go back on DS MDE or email account to accept the link so we could plan together. I also had to the do the same between the kids accounts so they could see each other (otherwise, I could see everyone, and they could only see me and DH in their profile).
I'm sure there were step I did that were redundant, but it seems like it worked.
For DS8, who was going to use my phone for the Play app -- Steps 1-3 is the same but on my phone.
Step 4 - create a new account -- but when I enter his birthday -- it defaults to asking for a Parent email and that's he's too young for his own.
Step 5 - check your disney email -- approve the request to create an account.
Step 6 - a little hazy on this -- I think I went back to the Play Disney -- and either went to a game that needed MB+ or to his profile and it *I think* prompted the QR code??? (it also gives a alphanumeric equivalent incase you're using the same phone)
Step 7 - on MDE (with myself logged in) go to Friends an Family - his name had the same greyish QR code symbol and enter the code in. It should now be linked and say "Linked Disney account Play" in grey.
i wanted him to also be visible to his brothers so I had to request a link from each of his brothers phones to him but since he's underage he can't "accept" through the email that gets sent to my acct (as the parent) -- bt somehow it still manages to link to him (probably because they are linked to me).
What I haven't checked yet is if DH can still see the kids on his phone's MDE (logged with his account). But he won't be the one getting the Virtual Queues or LL's.
Overall -- I think I have it linked correct but man, it took awhile to get the right configuration. At one point, I tried to do DS8 on DS13's phone and that was a mistake because it wouldn't let me take back the Birthday. I had to uninstall and reinstall the app. I'm glad I did all this in advance of the trip or I would have wasted time while in Batuu trying to link the darn things and gotten frustrated. It was also frustrating how long these things take to charge. So -- charge it, do the linking in advance. They better like this bounty hunter game and Ducktales after all this...
Good luck for anyone else trying to figure this out.