on a haunch I switched the computer from UEFI boot to CSM legacy boot. that did the trick.

I do not. linux quit booting for me at one point, so I had to turn it off.

I did not know how to check it previously. Looked it up, and the SHA256SUM's do match. I tried using etcher to flash the file over to the usb, and I used whatever is native to mint. Like I said though, I did it for a linux mint iso and that one worked.