Sync my devices fails for others

I recently reinstalled HA from scratch and integrating Google Assistant (the manual way) worked fine for the most part. My wife and I can both control all the devices that existed at the time of setup, and I can even use the “sync my devices” command to get Google Home to update devices and scenes. But when my wife tries that command Google says one or more devices were unavailable, so any new devices/scenes are unavailable to her.

I’ve tried changing her role in the Google HA project from Viewer to Editor and that made no difference. Anything else I can try?