The Chelsea coach is new in the Premier League, so he made the mistake of looking down on Ipswich simply because that the bottom of the table. Old coaches with experience in the Premier League know that every game is important even though it is obvious that you are going to win it. Chelsea will regret that game, because they were considered title contenders, but a two-game losing streak really puts their position in a lot of doubt, maybe they will qualify for the champions league, but not win the league.
It's not about experience but how a manager can analyze before the match starts and that should be the basis when facing a weak team because they might play beyond expectations. The Premier League is different because the weaker team also has the opportunity to beat the stronger team when the stronger team makes a mistake. I think there is a mistake that the Chelsea manager tried to apply by rotating at the wrong time so that Ipswich took advantage of the game to get three points.
If you look at the match statistics then it is clear that Chelsea should not have lost because they were quite dominant but there was a gap that was exploited by the Ipswich players so they managed to score an additional goal after the penalty was given. That is what I mean Chelsea lost concentration and they let the game run according to the flow and strategy of the Ipswich manager in defending.