Brother MFC-J6920DW Printer doesn't print duplex, Cups says print was successful

I have a brother MFC-J6920DW and have set up via CUPS several printers using the same hardware for different configuration. One of them is duplex printing. All of it worked fine until a few days ago. I do not remember anything special, that might have happened and caused the problem I am facing now:

When I start a print job with that configuration for duplex printing, the printer is first active, pulling in the paper, but then doesn’t print. On the screen of the printer it first says “receiving data”, and after a while “remaining data in memory”. Since nothing else happens (for a very long time), I press the “stop” button, and the paper is thrown out with nothing printed on it. CUPS says in the log that the print job was finished successfully.

In the errors log I find lines like this:

CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id \'MFC-J6920DW_A4-Duplex-Gray..\' already exists

I tried installing a new printer in CUPS (with the same hardware of course) with the same result.
The one-sided printing works fine, hence I rule out a hardware problem.
I checked in /var/spool/cups and found a lot of files there which I deleted, because they seemed to be directly related to the attempted but failed print jobs. But this didn’t change anything.
I have installed the printer driver provided by the AUR, it seems to be the one offered by CUPS, but I’m not sure. I tried all three different drivers (no idea where they come from) listed in CUPS,

Maybe try to delete the printer and then add the printer back in the CUPS configuration. In your web browser: localhost:631
Printers Tab-Administration-Delete Printer

Doesn’t help, it’s still the same. I restarted CUPS of course, after I did the change, but there’s no luck.

I just made an interesting observation: with the duplex printing set in CUPS, it just won’t print (as described in my first post). If I use the LibreOffice option in the print dialog to print duplex, the print works.

But then the LO print dialog gets in the way: if I want to print multiple copies (let’s say 10), I get by default 5 copies with page 1 on both sides and 5 copies with page 2 on both sides, which I don’t want obviously. The button for “sorted printing” (1,2,1,2,1,2…) is checked, so it should do page 1 and 2 on each sheet. But that won’t work initially. I have to turn off “sorted printing” (so it shows 1,1,1,2,2,2), then turn it on again, and turn off “individual print jobs” and then turn that on again, then it works (most likely). But printing is much slower this way, because it takes a long break in between print jobs, which I didn’t have when duplex was set in CUPS.

I am facing the same problem with the MFC-J6520DW.

I installed the printer with CUPS several times, trying different connections such as dnssd and ipp. The plain vanilla installation without duplex works fine unless I am trying to use a different paper (such as inkjet or photo paper). It seems somehow related to the paper selection.

I tried also to install the printer driver with the original Brother Linux-Tool, but this requires the deb file(s). Does anyone know how to overcome this?

Today I started a complete new installation - problem still there…

my saga continues, too. After it worked for some time, strangely with wrong bindings (short edge, when long edge was set and required, and vice versa), it now doesn’t print at all, neither duplex nor simplex. I also tried the testq I set up some time ago, no luck. Since I didn’t change anything at the config files or so, I am pritty sure it has to do with some altered settings or other changes made during an upgrade of the system. For at least 10 years I had no problems with brother printers and its drivers, why now?