That looks like it was from before the restructure just before the end of the season.
Edit: I just found an article on ESPN from the restructure on Jan 7th. It mentions the roster bonus for 2024 and that it is guaranteed on the 17th of yjis month. No idea why neither spotrac or OTC show it on his contract page though.
However doing a restructure of that bonus would increase this years cap hit not lower it.