So I just learned how to get the charging stats for a single day by long pressing on the chart in the Tesla app. Currently I have my charge schedule set to start at 11pm so the charging may have gone across days, which would mess up the results.Your Tesla reported 16 kWh used while the Tesla wall reported 20.7 kWh added to come back to 80%. So, the efficiency of charging is 16/20.7 = 77%
To have an accurate report you should charge your Tesla to 100%, drive it then come back and charge to 100% back. Usually the difference between the 2 values is 18-20% for Tesla Model 3. For the Tesla Y it is indeed about 22%. It is believed that it happens because Tesla doesn't count the kWh while parked. Or it really has a shitty on-board charger.
I'm going to change the charging schedule to start at 12:30am and then I'll redo the above analysis so I can also see the charging efficiency. and understand how much energy is used for purposes other than driving.