Just a note that I was still experiencing this on several APIs and it all but seems to "break" the current app's ability to manage existing requests or create new ones. Each time it happened I had to just start over and create a new app.
Finally saw from other threads here that turning off proxy requests could help, and that seems to have resolved the problem for now. Not sure if it's possible, but if the Editor could somehow recognize that responses are not updating (after a valid initial request), then provide some kind of text feedback in the panel for potential settings tweaks like the proxy toggle, that would've been immensely helpful. Even a small documentation update would be useful here. Honestly was starting to lose confidence in the tool, but happy to just focus on learning now 👍🏿