IN MY CASE I USED DIFFERENT CABLES, no luck still not detected by pc. but its charging. poco phone problem.
updated phone to the latest version, enable usb debug, usb file transfer as default. still not detected.
Before anything else,have you tried other ports in the Pc? Or have you tried other devices like a usb stick and if it works on any of the ports you connected the device to? If the ports work then follow the next steps:
Did you setup USB drivers? If not try that first as there may just be an issue with the driver. You can google "usb driver for poco" for more info.
If that doesn't fix the case, try putting the phone into fastboot and connect it to the PC and open ADB via a command prompt and type "fastboot devices". If it shows, then you likely have a bad firmware, recommend either flashing a new one completely
Or if that doesn't work then you may have to clear data completely (last option if your device is recognized via fastboot).
Now, in case the PC still doesn't recognize your phone even in fastboot then you may want to have a technician look at it further. I don't think it may be an issue with the phone's port as you said it was charging, but if everything else I've provided failed (those were software ts), then it likely might have something to do with the hardware itself.