I have a 2018 Mazda3 GT hatchback. It's less than a year old with about 4500 miles on it. It had its first service last month. Lately I've been noticing that it takes longer to turn over and stutters while cranking when it's warm. No problems with cold starts. Last week, I tried to do a warm start and it just kept cranking and stuttering until I turned it off then started up on the second try. No CEL and no codes.

It's currently at the dealer, but they're claiming they can't find anything wrong. They've tested the battery, starter, alternator etc. to no avail. I asked about fuel pressure problems and they said they would look into it. The lead mechanic is going to take it home tonight and see if he can figure anything out there.

Any ideas? Thanks!