That still doesn't explain why it has worked flawlessly for 6 months andall of a sudden has issues. Setup hasn't changed.

The issue is back out of nowhere again today! All of my flows adding order line items failed again with the same error messages. Haven't touched the flow or product listings.  

Agreed, my flows started magically working again overnight so clearly something going on with Shopify. But I'll take the quick fix!

I'm having the exact same problem out of nowhere today. I've been running this same flow for several months and have never had an issue.  Today, it now fails to add one of the order line items but successfully adds the other. The product listings and...