My printer is the HP Officejet Pro 8710. Not sure if they updated from HP. If they did, I went to HP and downloaded another set of drives. They installed just fine. But when I went in to add them by clicking the + button, no printers were there. It's odd. I'm going to try matching my Wi-Fi which is on 5G to match the printer 2G to see if that makes a difference. Really odd though. BRB.
Edit: That did it but let me explain the details. What I mean is, after the update, when my MacBook Air reconnected to Wi-Fi, it grabbed Wi-Fi from my Wi-Fi extender located in the back of my house. Which apparently has one bangin' signal even where it's located. Anyway, then I re-connected to my 5G band, the printers reappeared. Mystery solved.