AR: error message still here
ER: error message should disappear
To clarify, you're expecting the error message to disappear immediately, before you submit the form?
This sounds consistent and expected to me. Either we have JavaScript validation of fields, and therefore notify you of errors immediately so they can be resolved before submission or we don't.
Currently I don't believe we have any client-side form validation, at least none that I can think of.
I'm going to close this since there's no pathway forward that I can see. We might just not understand your request.
If you're expecting a client-side validation (i.e., the message to disappear immediately), we generally do not perform client-side validation, as @chad mentions. It would be very difficult given that you can set complex policy rules like "Subscribers" (so the policy might depend on what you type into another field). I don't currently ever plan to pursue this, as the benefits would be very small and the complexity would be high.
If your reproduction steps omitted a step like "5. Click save", I can't reproduce this issue. When I save the form, the edit goes through cleanly.
This report also does not include version information, but we're very clear about how important it is on the form you submitted to report this bug.
If we've misunderstood, please submit a new bug with more details and all the required information (complete reproduction steps and version information).