pxlcolor no longer prints Duplex

[jimbolaya]

Describe the bug
I seemed to encounter this issue once I upgraded from Debian Bullseye to Bookworm.
I'm not sure when this happened, but my printer using pxlcolor no longer prints duplex. I'm not even sure it's a pxlcolor issue, but after I upgraded if I use pxlcolor on my Dell 2130cn, it no longer prints duplex. The Foomatic/hpljs does work with duplex, but no color, not even hpljs-pcl5c. Also, CUPS+Gutenprint v5.3.4 works with duplex, but again, no color.
pxlcolor is the only driver I got to work with color, but no duplex.

To Reproduce
Steps to reproduce the behavior:

1. CUPS interface "https://localhost:631
2. Pick printer to change
3. Go past connection and other options to driver selection
4. Select 'Driver: Generic PCL 6/PCL XL Printer Foomatic/pxlcolor (recommended)'
5. try printing a test page. See two separate one sided pages (in color)

Expected behavior
I expected to see one sheet with printing on both. sides

System Information:

• OS: Debian Bookworm/12.5
• Browser Firefox
• Version [e.g. 22]

Additional context
I don't print a lot any more, but I'm almost certain this wasn't an issue in Bullseye. I'm not sure how to troubleshoot this further. I'll try to get a system up with Bullseye to check.