Cannot flash v12 w/ Balena

[heatr216]

Downloaded v12 three different times from https://www.mod-bros.com/en/mobro/download/latest?download-type=image thinking it might be an issue in transit. Used 7-zip on W10 x64 Home (just like I did with v11 and v10). Flash fails every time on balena 1.5.120. I have tried with two different USB microSD card readers (one I KNOW works, having just flashed Raspbian). One is USB-A 3.0 and the other, USB-C 3.0. Tried with verifying flash in balena and not. When skipping verification, the pi will boot and I just get a black screen, flashing cursor. Not sure what is failing...