I have a MacBook (Retina, 12-inch, Early 2015).
I have 2 USB keyboards, one at home and one at the office, that I connect through USB-C hubs that has USB-A ports. The hubs I leave connected to the keyboard and they're different brands, so I don't believe it's a hardware issue.
Both at home and at work, if I close the lid and disconnect the USB-C hub to go to a conference room or something, then come back and plug it back in at my desk the keyboard no longer works. Only way to fix it I've found is to restart the computer.
This happens both at home and at the office and the USB-C hubs are different and the keyboards are different.
This started last week after upgrading to Catalina (10.15) and continues after an upgrade to 10.15.1.