A fix for the database diagrams issue is coming in the next SSMS release (July 2020).
An error occurred while saving the commentJohn Calder commented
Same experience. I am an educator who has just lost over NZD 120 (approx USD 80) that I will probably need to pay for personally. OK I should have checked this out in Azure Calculator first but there was no cost warning when I created it. Also all of life experience is that firewalls like this are of lower cost value than servers and other machines so the experience on Azure is anti-intuitive and it needs fair warning.
Thanks for the valid suggestion. Your feedback is now open for the user community to upvote which allows us to effectively prioritize your request against our existing feature list and also gives us insight into the potential impact of implementing the suggested feature