With 102.3.x Thunderbird has changed the adressbook. All adressbocks (I also use nexcloud) are visible in the new thunderbird adressbook view, but when I write an email, I've no chance to type some characters and get suggest of other adresses in my adressbooks. So I've to open the new adressbook all the time, search there for adresses and click on the mailadress. This isn't a good workflow.
So please integrate all adressbooks to autofill (also in options there's only a way to set checkbox for the main adressbook) or roll back to former format of the adressbooks. Personally I find the the new adressbook format better (f.E. because of more "lines" for phone/mailadresses).
(Part of this text also add to an idea which votes for a roll back to old format, but integrating all adressbooks is better way in my eyes)