If the device can search for the Redmi Buds 4 Lite, but cannot connect, it may be that the Bluetooth data of the device is abnormal. Try to delete the previous connection record on the device, press and click either earbuds for 5 times to reset the device, and then try again. Try pairing to connect.
Delete the Bluetooth record on the mobile phone: Mobile>>Settings>>Bluetooth>>"Redmi Buds 4 Lite">>Unpair.