I did not have this capacitor between reset and ground. I put a 10uf capacitor in, and it worked. The bootloader installed correctly and functioned properly in my uno. I would have never figured it out if you hadn’t said that. Is it just something with the mega or do the unos need this too when burning the bootloader?
I feel sorta dumb for not selecting the bootloader, but anywhere I read on how to burn a bootloader with MiniCore, it did not say to select the bootloader option. It just skipped that step.
I was aware of this and was using the ICSP header.
Thanks everyone for helping me figure out my problem.
Btw when the bootloader is installed correctly, there is the led on pin 13 that blinks 3 times, pauses, and repeats the process forever until new code is written.
The capacitor on RESET is often also needed on the UNO. The purpose is to prevent the arduino running the Arduino as ISP sketch from resetting if avrdude does something with the serial connection that triggers the auto-reset.