Update identity null

Hi. Have been trying out Wappler and everything was going well with respect to viewing records, but cannot for the life of me edit a record (I know, right?). There is little in the docs or community areas on edit, which tells me that it must be so simple. There is the Wappler Unwrapped video, which I have watched several times, yet I only get this when doing a server action preview of a Update Database:

{“update1”:{“identity”:null,“affected”:0}}.

Oddly, when if going to Bootstrap Generator Form, with the server connect pointing to this server action, I am able to see the fields, but they disappear and are replaced by “#affected” when selecting “populate” to set the bindings, and only one field named “affected” is created.
Any thoughts, links, appreciated.