I contacted the customer to see if they had any insight into the Link Payment duplication

"I was called away while ordering and when I returned to finish the order the session had expired so I logged back in to finish"

How can the session expire in this situation in 3 minutes?

I have never used Link, so at checkout it does not show as an option. So I'm not clear what the customer sees or how a link payment can process without a Zen order being created