Do other devices charge normally with the same cable? Hopefully, using a different cable will be the fix. If not, this type of behavior could be indicative of your USB-C port going bad. You may want to head to a Samsung authorized service center, like uBreakiFix, for a free evaluation of your phone.
Yep, cables are typically the weak link. To be flexible, they're thin braided wires. Bending frequently over time and they'll break. Some last longer than others, and it's not dependent on price. I've gone with a style with 90 degree bend connector at the phone end and the frequent sharp bending is reduced. They last longer for my use then.
