This error appears for me from time to time.
I am creating a survey online. I open it in the connect app so I can add linked content to allow the survey to use a custom map, in this case Property Boundaries, and republish. Everything works fine and people are able to submit surveys no problem.
However, If I want to make a change via the browser to some of the settings such as what can submitters do? I can change the radio button option but when I try to save it says the survey doesn't exist or is not accessible. But it exists! I am in there and it works! 🙂 I will not rebuild this survey yet again to get to that option