Hi Miklós Budai ,
I apologize for the delay. We worked with our internal team and the issues is fixed.
A policy-AlertsManagement/actionRules- was blocking the resource creation for Microsoft.Although, Microsoft.AlertsManagement/* was enabled, we needed to specify action rules.
I have tried from my end, and it seems to be working fine now. Please get back to us if issue persists.
If you have further questions, please reach out to Microsoft Q&A forum.
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