Firstly, apologies for the delay in responding here and any inconvenience this issue may have caused.
Based on the error screenshot, the reason is "ConnectionFailedAdTrustedRelationshipFailure". This could mostly be issue with UPN being synced to Azure or because of user system domain issue.
Below are similar issue which has troubleshooting steps and hints on resolving the issue.
https://techcommunity.microsoft.com/t5/azure-virtual-desktop/error-when-connecting-to-mvd-0x3000047/m-p/1242145
https://github.com/MicrosoftDocs/azure-docs/issues/55687
Hope this helps.