SOC drop after charging is the system recalculating SOC after the battery has had time to settle and it can get more accurate measurements.
If you're experiencing huge changes, give the battery some exercise with full charge and full discharge, let it sit at empty for ~2h and then charge it up again. Repeat 6-10 times until it has recalibrated itself.
If you're experiencing huge changes, give the battery some exercise with full charge and full discharge, let it sit at empty for ~2h and then charge it up again. Repeat 6-10 times until it has recalibrated itself.