Since 09:12 UTC a monitor form that cannot be saved says Not saved. at the top and lists every field that needs attention, so an error further down the form is not missed. Each message also sits next to the field it belongs to; the verified-domain requirement, for example, is shown by the setting that asked for it, and a Basic auth error by the Basic auth fields.
Changelog ·
A refused monitor save says so at the top
When the monitor form refuses a save, a «Not saved.» line at the top names every field that needs attention, and each error sits by the field that caused it.