A friend visiting from India checked in to an AC Hotel in California. She presented her India Debit card (with a sufficient spending limit) at check-in. The front desk reported the card was declined. I paid for their stay. After check-in, she was asked for a card to cover incidentals. The same card was accepted and a 1$ token charge went through (later reversed at check out).

THe friend tells me her India bank never saw the initial transaction come through at their end.

She wants to understand what went wrong here so she isn't stuck in a similar situation in the future. Does anyone with knowledge of US Marriott reservation systems have an explanation?