Hello everyone! This is my first post here

I have created my firmware through kbfirmware.com and have imported my layout through keyboard-layout-editor.com. I have the DZ60 R2.0 PCB. After flashing, it exits DFU (flashing) mode like it should, and then immediately goes back into it! It does not do this with the default firmware. How do I fix this? I am using QMK Toolbox to flash it. Any help is appreciated! Thank you.
EDIT: I figured it out, my firmware was bad and I modified an existing (duplicated) and compiled it using this guide:
https://docs.qmk.fm/getting_started_make_guide.html.