What was your % when you plugged in? Has the car charged continuously since it was plugged in?
Are you in a condo or apartment? 204 volts would be OK if you are in a large building with 208/120 three phase power but low if you are in a single family house with 240/120 volts split phase power.
I'm not sure what battery you car has, but if it has 62 kWh capacity it would take about 4 hours to add 24 kWh to it at your charging rate of 6 kW. (62 x 38% = 23.56), which is about right for the time remaining.
To charge from 0% to 100% for such a battery should take a little over 10 hours at your 6 kW charging rate.
When the car is finished charging can you look at the charging stats in the Tesla app to see how much energy was added?