I may be having a similar issue with my <2 weeks old Macbook Air (Retina, 13-inch, 2020) running Catalina 10.15.4.
When I unplug cables from the USB-C ports then plug them back in, the port toward the back stops working. The power cable will not power the battery even when directly connected, nor will any other USB-C device work through that port. I can reset the SMC to restore functionality. Sometimes it takes a couple of resets to make it work again.
The problem recurs every time I unplug the USB-C cables from the laptop.
That back port is usually occupied by a hub that has Cat-5 (ethernet), HDMI, and power. The front port has an HDMI to USB-C cable. The same problem occurs if the two are switched, and as stated before the port doesn't work even if I bypass the hub and plug in the cables directly to USB-C.
The port closer to the front of the laptop seems to work reliably.