I created a google addressbook. The main address list works fine, but the groups are all empty. Manually syncing does not help. Reproducible: Always
This bug has never been confirmed for a Kontact version that is based on KDE Frameworks, except possibly a Technology Preview version 5.0.x. Those versions differ significantly from the old 4.x series. Therefore, I plan to close it in around two or three months. In the meantime, it is set to WAITINGFORINFO to give reporters the opportunity to check if it is still valid. As soon as someone confirms it for a recent version (at least 5.1, ideally even more recent), I'll gladly reopen it. Please understand that we lack the manpower to triage bugs reported for versions almost two years beyond their end of life.
Is fixed now. Working with groups doesn't really work anyway (dragging a contact to a group does not add it to the group in google), but that's another story.