Gmail syncs but no messaes appear

I Recommended emclient to a friend since she wanted a desktop email client and she is not very tech savy and didn’t want the bloat of outloook. She installed it, configured a gmail account using the wizard and authenticated using oauth. There are no messages shown in the inbox. Neither new nor old, read nor unread. The folders sync (I can see a list of her custom folders) but all folders (special and custom) show 0 messages. I even tried moving the database to a new place so it regenerates but still no success. I Can’t catch any errors in the logs. BTW sending emails works perfectly (messages are sent) but still are not shown in SENT folder in emclient (nevertheless they appear in gmail’s web client) Thanks for your help