Hi Luke,
I want to apologize again that this issue has caused you inconvenience.
I had a chance to connect with our Support and Development Teams. The issue that you experienced could have been a result of two independent conditions:
1. With Network Objects enabled, the issue can occur when sequential steps were taken during L3 Firewall Rule configuration.
2. Unrelated changes (L7 or Forwarding Rules) on the Firewall page.
Our Development Team has deployed fixes for both of the conditions above. You should not expect to experience the issue again. If you do, please immediately reach out to Support. We'll be able to appropriately triage the case. We also see that you have already added back your lost firewall rules onto Dashboard.
Please let me know if you have any additional concerns.
Thank you.