Can you post your config.g, homing files, the results of M122, and M98 P"config.g"? That will give us a lot more useful information to go by. You could also export your cura project as a .3mf and post it as well.
I'm sorry your Duet has failed. Please submit a warranty claim. Also, please answer the following questions:
Please read off any letters and numbers you can read on U3.
What VIN voltage were you using?
What (if anything) were you powering using 5V power from the Duet? For example: PanelDue, 5V fans, servo, BLTouch.