Default [Battery] Why Does Battery Level Jump to 100 During Charging!

Please look at the end of time axis. During the charging, the battery level jump from 78 to 100 suddenly.

I found similar jumping several times, and I did a calibration by completely discharging the battery. During discharging, the last 1 percent is supper durable. However, after a couple of days, the jump reappear again.

Any ideas?
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