There may be several reasons why the Mi 13Ultra does not display supercharging:
Non-original charger or data cable: Xiaomi Super fast charge technology uses the USBPD (PowerDelivery) fast charge protocol, which supports power transmission up to 100W, but only when using the original charger and data cable can activate the super fast charge. If the charger and data cable used are not original, it may cause the supercharge to not show.
Original charger or data cable damage: If the original charger or data cable is damaged, it may also cause the super charge to not be displayed.
Phone system failure or Settings: If the phone system is faulty or the Settings are incorrect, the supercharge may not be displayed. In this case, try checking your phone's system Settings or seek professional help.
If you are sure to use the original charger and data cable, and the mobile phone system is not faulty, then it may be the problem of the phone itself, it is recommended that you contact the Xiaomi customer service center for inspection or repair).