Today same thing happened to me. I also was usinng the official power adapter. At first I noticed the power wasn't going to the pi when i insert it normally, i only got power when pushed it to the right a bit. i installed the case and was willing to use it like that.
but after a while it stopped working competely. and when i removed the case the port just fell off.
I think it warrants a quality check of production lines. it not only fell but was also defective. the foundation's luck hasn't been great with the new usb-c port somehow :p first the lack of resistor and then this.