Waveshare 7.5 inch HAT V2 flashes but does not successfully run sample demo

[josephkimsungha]

Hi, I've been struggling with this for many hours at this point. I am working with a Pi Zero 2 W (with pre-soldered male headers, i.e. I did not attempt it myself) and a Waveshare 7.5 inch HAT V2.
I followed all the steps on the Waveshare documentation page (https://www.waveshare.com/wiki/7.5inch_e-Paper_HAT_Manual). Specifically, I made sure to enable the SPI interface and reboot before installing all the dependencies and running the sample code at https://files.waveshare.com/upload/7/71/E-Paper_code.zip

This is what I see, along with just a stream of Paper busy, Paper busy release on repeat in the logs.

waveshare.display.mp4

I attempted both C and Python samples but got the same result.

Any help would be extremely appreciated!