@Richard Xu - IT , GG, Goldman, Joshua, @Jean Fabrice - Thanks for reaching out here and sorry for your experience because of this issue.
As per my internal investigation, looks like this issue is caused because of recent change in the service side. The respective product team has applied mitigation and confirmed that the issue should be resolved to the end users.
Kindly refresh or reopen Synapse Studio and let me know if you still experience the problem. In case if the issue persists, kindly share your Synapse Workspace location so that I can double check with internal team on the same.
Thank you