Has anyone booked a ticket via Vietnam Airline website?

When filling in information for a passenger, it requested "Middle Name & First/Given Name" as one of the field. I am confused as to why the request is for Middle Name ahead of First Name in the field. And to compound that, my middle name is 2 words with a space in between, e.g. "MM1 MM2"

So should I enter "MM1 MM2 FFFF" in the field (per website's request), or "FFFF MM1 MM2" in the field (as I would normally be filling in for other web page)?

Bottom line is that the ticket should show "FFFF MM1 MM2 LLLL" to match my passport name, which is First Name followed by Middle Name followed by Last Name.

Help please!! Thanks in advance.