When a reviewer is adding an unavailability period, the button to commit the form is labelled "Add period", which is very similar to the "Add a new period" button which opened the form in the first place (and is still on the page with the form it opened).

This is very confusing.

The button to commit the form should include the word "Save" (or otherwise indicate that this is the "take my input" action, not a "I want to do more" action.)

It's a game of bring-me-a-rock to figure out how to add multiple unavailability periods if you show up at the form for the first time wanting to do that. The page should make the workflow to do that obvious.