Airtable: record update is creating new instead ...sometimes

I’ve got my Airtable data connection updating a record perfectly - when I test it on the data tab. But when I try to do it while actually testing it on the web or on a mobile device, it creates a brand new record instead of updating the one it is supposed to.

I’ve watched the communication of the record ID travel from the initial rendering of the data, through choosing it, and then after the record supposedly updates - confirming the node uses the same text-variable ID as when the original record was initially read. But when the page returns to where the initial record should be updated, its not - but there is a new record with a new ID listed.

Is this a bug with the Airtable API?