The charger and cable is fine and charges other phones normally.
When I plug in the phone, charging starts to "pulse" in regular intervals (charges for a small fraction of a second every second, the phone vibrates every second as if I was continuously plugging the charger in and out). I have tried multiple chargers and cables, some don't work at all, but I have found one charger that charges the phone slowly in one particular orientation of the usb-c connection. I assume it might be a hardware problem of the usb-c port.
My phone is still under warranty, should I return it or is there any troubleshooting step I should try first? Booting into safe mode did not help. I have also tried blowing compressed air into the port to get rid of any dirt but sadly that didn't help either.