@DTS Engineer Thank you for responding, I just see your reply. [1] What actually happens when you plug the device in? The mopai kt393's usb otg ports work normally when i plug any other device such as ssd, hdd, dac dongle, flashdisk, even i connect the otg to another usb hub which has rj45 port. Also when i plug charging port, it provides power to connected ssd, hdd, etc, but not giving power to my 14 pro(ios27). The weird case is that when i restart my 14 pro(ios27) without unplugging the charger and mopai kt393, after the phone's booted, it starts to charge. But when i unplug the plug again, it won't charge. So the problem now is that i must restart my 14 pro(ios27) everytime i have unplugged the mopai kt393 to be able to charge again. The other phones i tested were 14 pro(ios18) and 13 basic(ios26), they were charged normally without need to restart. [2] Do you get a warning about the accessory being uncertified, or does "nothing" happen? No warning and nothing happen. [3] Also, is your phone able to charge through other sources? My 14 pro(ios27) is normally charged using any lightning charger(without plugging to usb otg). [4] Finally, have you tried restarting the device? Yes, i answered on question 1. Please help me to solve this problem, thank you so much.