How to access printer instances from browser dialog

[mcp292]

I'm using Firefox 115.0.1 (64-bit) on Arch Linux.

I have an instance (siccs) that works from the commandline, but from the browser dialog I see two printers and neither print according to the instance configuration:

[debiantriage]

This portion of the Firefox print dialog should only show local printers. Let's have lpstat -t.

What does

Print using the system dialog...

display?

[mcp292]

Thanks for the help!

lpstat -t
----
scheduler is running
system default destination: brother
device for brother: ipp://BRWAC50DE53C9BC.local:631/ipp/print
device for siccs: ipp://10.5.109.85
device for siccs/duplex: ipp://10.5.109.85
device for xerox: usb://Xerox/B210%20Printer?serial=HAQ704348
brother accepting requests since Wed 05 Jul 2023 10:04:30 AM MST
siccs accepting requests since Tue 11 Jul 2023 10:37:36 AM MST
siccs/duplex accepting requests since Tue 11 Jul 2023 10:37:36 AM MST
xerox accepting requests since Fri 12 Aug 2022 09:19:23 AM MST
printer brother is idle.  enabled since Wed 05 Jul 2023 10:04:30 AM MST
printer siccs is idle.  enabled since Tue 11 Jul 2023 10:37:36 AM MST
printer siccs/duplex is idle.  enabled since Tue 11 Jul 2023 10:37:36 AM MST
printer xerox is idle.  enabled since Fri 12 Aug 2022 09:19:23 AM MST

System dialog only shows one siccs printer:

[zdohnal]

It looks like Firefox and GTK dialogs don't support instances right now :( (tested on Fedora Linux 38, Firefox 115.0)...