Printer is printing gibberish after OS software update to IOS10.14.3

[Thud1]

Printer was working fine yesterday.  I updated the OS to IOS 10.14.3 this morning, and am getting gibberish out of the printer now.  Initially, the printer was not even on-line with the computer, and finally it was reconnected via wi-fi.  But it is printing all G's and J's, except for the letterhead of the document.

[senan6806]

@Thud1

A warm welcome to HP Support Community!

Since the issue started after the update, its possible that the printer driver installed on your Mac is corrupted or damaged. Most of the HP printers uses driverless technologies such as AirPrint or IPP, which don't require additional drivers on your Mac. Removing the existing printer driver and setting up the printer with Apple AirPrint may resolve the issue. If the printer is connected to your home WiFi, then you may use the following steps to setup the printer with Apple AirPrint.

Please ensure that the printer is up to date with its firmware and Mac is up to date with it's software. If you are unsure you may use the links below to update the printer firmware and Mac software:

Update printer firmware

Update software on Mac 

1.) Click the Apple menu, click System Preferences, and then click Print & Scan or Printers & Scanners.

2.) Check if your printer name displays in the Printers list, If your printer is listed, click the printer name, click the minus sign to delete the printer.

3.) If you see multiple printer queues for the same printer, remove all extra printers by selecting them one at a time, and then clicking the minus button  at the bottom of the list.

4.) Click the plus sign , click Add Printer or Scanner, click the printer name.

5.) Click the Use or Print Using menu, select AirPrint or Secure AirPrint in the pop-up menu. Then click Add.

6.) Try to print.

If the information I've provided was helpful, give us some reinforcement by clicking the Accepted Solution and Kudos buttons, that'll help us and others see that we've got the answers!
Have a great day!