Intermittent black squares printing from Pioneers to 82240B

[BobVA]

That is puzzling. Dropping the first character sounds like possibly a timing issue, like the head isn't returning quickly enough to keep up with the data?

Long shots, but maybe worth checking:
- Double check the Battery / AC Adapter setting; maybe change it to AC and then change it back to Battery, just to make sure it's being read properly by the 27S.
- Try running the printer on an AC adapter if you have one or, if not, try another set of fresh batteries just to make sure it's operating at full speed.