Sounds very familiar. I had this, single charger down to 1.3 kW. Long charge time! Weirdly it started charging went to 2.3kW, then immediately dropped back to 1.2/1.3kW. Note this behavior was immediate upon a software update which said it offered better battery management...
I took it in for a new battery ( separate story) and the dealer (DAVANT, Uk), looked at it and said that the fans on the chargers weren't working. They blew compressed air through the stationary chargers and got a lot of muck out (!) and the charger fan then started (I knew a noise was missing, could not work out what it was..) it took them a while to get it up to 2.2/2.3 kW.
Sadly, I have to say that I have the new battery, but the charging rate now starts at 11.6 kW (Premium and charge tank), but then drops fast. at 61% I'm only charging at 6kW, by 80% im only doing 4kW, etc etc. On the bright side the SOC seems better prediction and I dont have magic charging anymore.
I thought this behavior would disappear with the new battery, Hoping it was a simple software issue, and I'm not that impressed with the cleaning by compressed air injection, My first guess is a charger gone or on its way out.
I would really like to monitor the charge rates over time, ideally to see each phase contribution, which should ID any poor charger. Anybody any idea how to do this?
So, does yours ramp up to 3/2.4kW and then straight down? Can you hear the fan(s) start up at the beginning? worth a look.
PS haven't fixed mine yet, in the email ether to Zero...
pete