I looked it up and the 5 losses were:
Yesterday
vs Philly in OT
Miami when they played on the surface of the sun
Vikings in OT
TB in OT
So I would say yesterday and against TB were the only two games where they were trailing big. The Philly, Miami and Vikings games were more back and forth games.
I do agree that they tend to stop trying to beat teams when they get up 2 scores and put the offense on cruise control which is a mentality I will never understand. You're basically inviting the other team to get back into the game.
I'd also venture to guess a good amount of the wins from Mahomes were when he still had Hill on the team to get those 400+ yards.