I'm not sure why this is happening, but every now and then the Epson TM-M10 will print gibberish. Have to turn printer off and on again to get it working again.
Intermittent - works great most of the time.
iOS with latest iPad and Stand.
Have you reached out to Epson to let them know you are experiencing this issue? Since it's a 3rd party who makes this printer, they may have troubleshooting steps outside the normals connectivity ones Square can provide. Sounds the hardware may need a firmware update.