It does sound like one of the two black inks “pgblack” or regular “black” is still clogged — if you can print okay in other situations but not text in apps like Numbers, I think that’s the problem.
Wait a few days before doing another deep clean. It’s very wearing on the print heads and should not be used routinely.
If that doesn’t work, it’s time to reevaluate your print needs and based on that, consider a new printer.