The USB C connection on my laptop loosened over time. To the point that the cable now just falls out unless I keep the laptop completely still. Having a magnet in there to keep the cable in place would be nice. No reason you couldn't use a magnet with a USB-C connection though, best of both worlds and whatnot
It's also possible you have lint in your connector. Try poking around for a while with a thin non-metal object (e.g. toothpick). If you keep your phone on your pocket you'll need likely get lint in there with time.
