Apple USB-C cable is recognized as a UNSUPPORTED device and won't charge my macbook.

Hi di269.

The message you see on your phone “Unsupported USB device” that appears when you plug-in the Apple C type charge cable is symptomatic of a breakdown and short circuit between the data carrying and power carrying wires inside the cable.

This cable should no longer be used as it may cause damage to connected devices and may also pose a fire risk when plugged into unregulated third-party USB charging ports.

Verify that replacing the cable with a new cable restores charging to your laptop and that the “Unsupported USB device” message no longer appears when used to charge your phone.

HTH.

Will.

di269 wrote:

I have a macbook pro 2019, with the original charger and type-C charging cable.

My type-C charging cable no longer charges (the charger is okay because it charges my laptop if I change a cable)

Interesting thing is, if I use this cable to charge my Samsung phone, my phone says "recognized unsupported USB device", which means my phone doesn't treat it as a power source, but a malfunctioning USB device.

So replace it.

If you are still under warranty call AppleCare Support at 1-800-APLCARE (800-275-2273)

Check your coverage

https://support.apple.com/my-support

Find the right power adapter and cable for your Mac notebook ...

https://support.apple.com/en-us/HT201700