I found the M5Burner tool and tried some different firmwares. Really, just guessing. I tried M5Fire-v.16-psram, since that's most applicable to my device, but the end result was the same.

Eventually, I found M5Cloud-v-0.4.0 which does work. However, that only lets me code in Python, which is not what I want. But I guess I know I have a working device. If only I was in 3rd grade Python class, and not trying to run my ESP3266 data logger that I wrote in C.