A different problem with new credit card online sync

[Paula Maas]

Our bank changed our shared credit card to two new accounts. The "Online 
banking setup" is greyed out for either of these accounts, even when one 
is linked to the main account holder.
Nor is that an option, or online actions, with my old account, so I 
don't see how to merge the new (2 accounts) onto where the old account 
was. The bank employee told us that
either user account would bring down both user's expenses as though it 
were one account. I've uninstalled, re-installed GnuCash, deleted and 
reformed accounts,
and can't figure out what's going on. Would be grateful for any help. 
Gratitude in advance, Kind