Airtable changed the way it handles attachments (see https://support.airtable.com/docs/en/changes-to-airtable-attachments) in November. It specifically says “Any attachment URLs obtained via the Airtable Web API and the CSV export functionality will expire after a few hours.” Since you’re using the web API to get the attachment from Make, I think that the link to the attachment is expiring.
PS: what I know about APIs is virtually nothing, so this conclusion might be completely incorrect.
I'm having the same issue and can't seem to figure out why? Hopefully someone can enlighten us.
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