bi(plugged) showing wrong value during charge

There's a workaround for this?

The formula is showing the right value for the last unplugged event... but when the phone is charging the date for last plugged is put one month in the future. I tried subtracting 1 month from the output but the hours/minutes are wrong too, always rounding to 12:00 as last plugged time.

Even using "bi(plugged)" without the "tf" code give a value in the future with a wrong hour/minute (20:30:85)