Black wont print after Firmware update - Officejet 6958

[dragppo]

I have an issue where, after a firmware update in May 2021, the black ink stopped working.

- The black ink worked fine until I selected "update" on the printer screen (now its on Firmware MJM2CN2109AR.00)

- Most documents print the color portion but not the black portion (if I print from my android I get the outlines of font but it looks grey because its only the outlines) - no black ink if i print from Windows 10

- Its a new cartridge and Ive run the "clean printerhead" 5 times, through all 3 cycles (new cartridge has been thoroughly drained due to this, so I know its not clogged and has nothing to do with the printhead )

- Ive tried everything in the manual as well as various forums on HP and nothing works

- There is no way to factory reset the darn thing because if I click the back button 4 times I only get the options "partial reset" and "semi-full reset" as an option

Is this an issue with my firmware? how can i fully factory reset the thing to its original firmware? is there a way to downgrade my firmware?

update - I'm throwing my hands up in frustration, a day later, its now working. I thought I had nothing to loose by running the "clean printerhead" again today, on the 3rd run through (3rd run though of all 3 cleaning cycles!) it printed a little black! on the 4th run through (2nd cycle) it was able to print a full diagnostic test sheet.

Suffice to say, just keep running the darn "clean printer head option until it comes through (maybe let it sit overnight to soak the line in ink? the cleaning bay on mine is drenched in black ink though - I put a papertowel in there to soak up the ridiculous amount) - HP got its moneys worth out of this, now wasted, black (K) printer cartridge. im off to buy a new one...