Rated 5 out of 5 stars

Same here for me: After yesterday's update the Google-Sync is broken. Although in my google-account Cardbook has access to my contacts - Thunderbird says that "the app is blocked". Please fix that, thank you very much!

This review is for a previous version of the add-on (55.5). 

retry a bit later... for me it works on different PC and different email account....

workaround here : https://gitlab.com/CardBook/CardBook/-/issues/1172#note_512218318