Many NFL teams have former Colts and Lions coach Jim Caldwell on their short lists for various positions, but he has turned down at least one interview for a specific reason.
The Washington Commanders are among several teams that wanted to speak to Caldwell about their vacant offensive coordinator position, according to Mike Garafolo and Ian Rapoport of NFL Network. However, they were told that Caldwell is only considering head coach positions at this time.
Would've been a rockstar hire for the #Commanders. But they join a long list of teams who have tried to interview Jim Caldwell for OC, only to be told he'd a HC and that's it. https://t.co/BF4MswNyw6
— Ian Rapoport (@RapSheet) January 13, 2023

Caldwell’s last stint as an offensive coordinator was in 2013. He had coached the Colts before that, and took over the Lions after that. He clearly sees himself as having proven himself as a head coach, and he is not necessarily wrong to.
Caldwell is getting looks for head coaching positions, and that was true last offseason as well. There were reports that he even turned down some head coach interviews at that time, but he denied those publicly.