I am having the same exact issue as someone posted back in XXXX here:

Retrofit kit showing empty zone as open

I have 6 active zones and zone 7 and 8 are not connected to anything.
However, Ring is reporting them as ‘Open’ and there is no way to delete them from the app.
When you open those zones in the app it says ‘Testing your connection…’ and can’t do anything with it.

I already called support about this when it happened over a year ago. Their only solution was to reset the retrofit kit and setup all the zones all over again. So that “fixed” the issue for a little bit then it happened again. I am not going to reset the retrofit kit each time this happens. This is clearly a bug with this product but Ring support has no solution for it.

Did anyone find a fix or a workaround besides resetting the kit or just ignoring the fact that the app keeps reporting empty zones as open?

Thanks