Under normal circumstances, the fast charge disappears after the Xiaomi 10pro upgrades miui12, which may be caused by the abnormal charger or data cable used, which can usually be solved by replacing the data cable. It may also be caused by a system anomaly, which can be solved by restarting the phone.
Xiaomi 10pro supports fast charging, if not fast charging may be because the charger is not a fast charging appliance, it may also be a problem with the charging module of the phone