Why is printing from other VLANs impossible with the dream machine?

I've had a dream machine for over 5 years, and printing has never worked correctly. I have 4 VLANs (well, 5 if you include the printer-only vlan4 I just created)

Default
WFH
IoT
Printer
Guest

None of my VLANs are isolated except for guest and printing is an adventure every time.

There are many posts about fixing the printer issue and none of them fix my problem. I now have more printer specific firewall rules than I'll ever need, but none of them allow printing across VLANs.

Why is this so hard? Haven't printers been around for decades?

I wish there was a "Press this button to make printing work" button.

I think I know enough about subnetting, firewall rules and VLANs to figure this out, but nothing seems to work.

Any suggestions?