I see, I will try to clean it.If the head is clogged, try following the steps at this link: https://www.firebirdink.com/saving-printhead-firebird-last-resort-solution/
You don't have the Last Resort solution that article is meant for, but you can try following the steps with regular cleaning solution. This is not a guarantee, and some clogged heads can't be recovered.
You're much more likely to have problems with your printer if you allow it to sit with ink in it without cleaning or printing. While some printers are lucky and have conditions that prevent this, it sounds like you were already seeing some settling in your lines from letting the printer sit. This is an issue for all brands and is worse for the white ink than CMYK.
So do you have any idea for maintenance? Print it every day?