Can't overwrite build or start commands

When I enter something in the build or start command fields and click "Check", the edit mode is just turned off, and nothing is saved. I tried both Arc and Safari, same result: Steps to reproduce: 1. Click the "Start command" button 2. Enter a value such as go run api.go 3. Click "V" (checkmark) Expected result: The command is saved. Actual result: Same as if you click cancel.