Why my phone won't charge until I flipped the USB-C cable from the adapter?

I have an Apple charger & USB-C cable from about 2 years ago.

Now, when it's charging normally, if I unplug and plug it back in, it won't charge anymore. Removing and plugging back the adapter from the outlet won't help.

However, if I flip the USB-C cable from the adapter (when the adapter is not connected to the outlet), the phone says it's charging for like 1 second. And now, I can plug the adapter to the outlet, and it will start charging like nothing ever happened.

Now, I can plug out my phone, and plug in, it stops charging and I have to redo the process I've just mentioned. It always work like that, just like that's how it programmed.

Anyone here know what's going on and what should I do? Thanks.