Dealer refuses to look at the until problem goes from intermittent to constant.

2015 Mitsubishi Engine Noise 1.2L
Happens for 30 seconds during cold start. Then sometimes comes back 1 minute later for another 30 seconds.
Car has only 31k miles on it.
Dealer refuses to look at it until noise becomes constant instead of intermittent.
Any clues?
Did not start happening until yesterday.
Car had 30k mile service @ 29.3k miles a few months ago and checked fine at the time.

Thank you

https://youtu.be/-a54iTpRL5o