Confused about "Nozzle Out" data

According to this video, the printheads with problems are the ones with long strings of letters after them in the printer data page.


However my printer data page shows long strings of text after the printheads that are practically brand new. I know new printheads can fail, but to have 3 of them fail?

I'm also not sure how to read the printhead plot. The manual just says "make sure most of the dashes are there".