Hello @Mareš Petr , the Entra ID (formerly Azure AD) AADSTS53003 is caused by one ore more Conditional Access policies blocking you from signing in or accessing a resource. In your specific scenario it were 3 policies. For more information or how to avoid facing this issue again please reach one of your tenant admins.
Let us know if you need additional assistance. If the answer was helpful, please accept it and rate it so that others facing a similar issue can easily find a solution.