I am running Ubuntu 18.04.2 Desktop on my laptop.
I have installed CUPS to a Raspberry Pi running Raspbian. My Mac will consistently print to this printer without any problems.
From Ubuntu Desktop I am only able to print to the printer ~1 minute after a reboot of Ubuntu Desktop. After that time documents will not print.
When I visit ‘localhost:631’ from Ubuntu Desktop the status is listed as ‘Idle - “No suitable Destination Host found by cups-browsed”’ (see attached).
Images can be seen here https://imgur.com/a/mm4WzMS