Sorry if I was stating the obvious, but you didn't use the m-word and so it wasn't clear that it was. Particularly as you didn't mention trying any of the solutions in that article. You only mentioned alignment and that's not the issue here.
I have had misfiring nozzles from time to time and generally head cleans of various kinds and/or printer cleaning routines as per the IJM videos have worked, but these instances were only with desktop printers. That said, you'd think the same principles would apply to LF printers. I think the 7880 still uses a DX5 print head.