Tray defaults work as follows on HP. The highest number tray is always the default if it contains the default paper size and type. The default for your geographical location would normally be A4 size and plain type. If you set tray 2 settings on the printer itself to that then the printer will take that paper first. If you have changed the default paper size or type on either the print driver or printer itself then you need to make adjustments so that they all match.
If you find the information provided useful or solves your problems, help other users find the solution easier by giving kudos and marking my post as an accepted solution. I am a volunteer, offering my knowledge to support fellow users, I do not work for HP nor speak for HP.
Be alert for scammers posting fake support phone numbers and/or email addresses on the community. If you think you have received a fake HP Support message, please report it to us by clicking on "Flag Post".