I am currently away. Last I spoke with the dealer, they said that it took their techs two days to download and install six missing software updates, which is the standard first step. My 2021 car is an early model and does not have full OTA (which Teslas do have), and so the out-of-date software packages tend to accumulate until the car sees the dealer. They said that the software updates were successful, but didn't fix the issue. Apparently they have since opened a 'technical case' with Hyundai and are awaiting their instructions.
I told them that I will be back in the UK in early March, and they have until then to try and fix it... In the mean time I get notifications on my app from time to time that the car is being charged, so they must be doing something with it
From reading online, it's definitely a cell imbalance issue - though the resolution is unclear. They may be able to rebalance the cells using some software trickery, or they may need to replace one module, or they may need to replace the entire battery pack... no idea.
