@Grump_y, Welcome to the HP Support Community!
I understand Cyan is not printing right. Make sure you have tried the steps mentioned in this document - Black or Color Ink Not Printing, Other Print Quality Issues
Check the ink level and replace it if low. Check if you receive any errors regarding the cyan ink cartridge.
If the issue persists, please reach out to the HP Technical Support team in your region regarding the service options.
You may create a case on the website to obtain a case number if required. Kindly watch this video to know how.
Keep me posted for any other assistance.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.
Click the “Kudos, Thumbs Up" on the bottom right to say “Thanks” for helping!
Have a great day!
KUMAR0307
I am an HP Employee