Hi Yiming,
I have no sync problems when using Epics.
I also have an issue syncing Stories.
For now, use Epics and report a bug.
Edit: in this solution: https://forum.mendix.com/link/questions/120729, it starts to work again by switching back from Epics to Stories again. Maybe something to try.
Go Make It
Hi,
According to Mendix Docs,
“As of the GA release on December 1st, 2022, Epics is the default project management tool for all new apps.”
You can still use stories by going to general settings and using the option in screenshot below:
For more info, please read: https://docs.mendix.com/developerportal/collaborate/epics/
Regards