Here is a "Knowledge Article", in 'FamilySearch':
Where, it states, among other things:
I hope, that this may also help/assist, somewhat.
I am just another 'lowly' User/Patron ...
Just in passing ...
'FamilySearch' Accounts, for the same User/Patron, can NO LONGER be joined together.
Pick one Account; and, close the other.
That Said ...
BEFORE, you close the relevant Account ...
For the Account, that you decide to close, make certain, that you Copy/Transfer ALL the "Information", from that Account, to the Account that you have decided to retain.
Then, you can close the the relevant Account.
I hope, that this may help/assist, somewhat.
Thank you for your help.