If you've got a bug in gufw then start here:
Pedant. I was trying to keep it simple for the OP's benefit. Lots of folks see SQL and DDL as a single somewhat ugly amalgamation.
Are you joking? That pile of junk hasn't been updated since 2015. There are much better ways to control GPIOs now (usually using RPi.GPIO, GPIOZero and/or PIGPIO/pigpiod).