I have an issue with the Add-On Cardbook in it's latest version (97.7) as well with last version I knew that worked with Thunderbird 128.5 which was 94.4 of Cardbook. Upgraded to Thunderbird 128.5.1 the latest version of Cardbook can't migrate all my contacts. With the lower version in use it can't synchronize my Google-Account-Contacts within 5 Minutes. Indeed it took several hours to synchronize and show 21 of 113 contacts. This happened before when I tried to update Cardbook, but then was it able to synchronize with Google within less than a minute.