I suspect that Artemis still lacks the ability to accurately monitor and correct a near-moon orbit. The only close approaches were on entering and leaving lunar orbit. The moon has several mass concentrations that influence any close orbit and because of this, a lot of checking and correcting was needed during the various trips around the moon that Apollos 8 and beyond carried out. Basically, the gravitational field around the moon is far from uniform. Or perhaps Artemis has that capability, but they decided to play it safe for a first outing.