Just so you're aware, Matchmaking for Firestorm has been temporarily disabled while the Devs work on a Hot Fix.
More info here: https://twitter.com/Braddock512/status/1143554685984313345
Thanks for the Intel, @iluminatethesky!
The team deployed a backend hotfix to address the issues with Firestorm matchmaking and it should be available now. Thanks for your patience!