Hello @Antonin Jelinek (CZ) ,
Thanks for reaching out to Microsoft Q&A.
Probably that VM is not available for your subscription under SPOT instances. Did you try by un-checking the SPOT instance flag ? Also try deploying the same SKU by removing zones.
What is the error Key code you were getting ?
As per the document , search for the error key codes here : https://learn.microsoft.com/en-us/azure/virtual-machines/error-codes-spot
Check out the SPOT VM limitations: https://learn.microsoft.com/en-us/azure/virtual-machines/spot-vms
Regards,
Shiva.