It's likely this issue:
VCMS TSB Now Out for Intermittent Lvl 2 Charging Issues
Fix Level 2 Charging Problems with this New Technical Service Bulletin! https://youtu.be/2UlxyXtTNRQ This TSB tackles the level 2 charging issues Ioniq 5 owners in the US have been having for over a year now. It’s mostly a problem for people charging at 40A or higher. Attached is a copy of...