Hey. The board setup looks good. I’m pretty sure you’ll get it to work.
Have you double-checked that the microcontroller is powered with 3.3V?
I’m not sure what I should look at in the firmware. If you made changes to the firmware, please provide a link to a git repo so that I can spot which changes you made and double-check them.
Also I would suggest to use the most recent firmware released today.
which programmer hardware are you using? Do you get any error message back? Did you have double checked that the program lines are in the right order an not swapped? If you use a pullup-resistor and a capacitor to GND on your reset line, try to remove the capacitor because the capacitor can disturb fast signal rising on reset.