Hi @demo case ,
Welcome to Microsoft Q&A Platform. Thanks for posting the query.
I was able to reproduce this issue when the workspace is not properly provisioned. Please check overview page of workspace and if you can see the error as below, please check deployments as shown in another snap below to understand for any issues while deploying the synapse workspace. Please check using PowerShell commands if no error message is seen in overview page using commands.
Hope this helps! Please let us know if issue persists and we will be glad to assist.