TurboPrint & PrintFab

Hello,
I am using Ubuntu 23.04 and a Canon Prograph Pro-300 printer. I convert my RAW files to JPEG using Darktable. I print the JPEGs with GThumb.
I am trying to print 4 pictures on A4 paper (Canson Infinity).
When I start printing with GThumb, I have to choose a layout for the 4 photos: portrait (with the photos at 90°) or landscape. The 4-part image preview is always perfect.
After clicking on ‘print’, TurboPrint launches and gives me a preview. Unfortunately, the layout is always portrait and the photos are systematically misaligned and cropped. I don't understand which settings I need to change.
I am attaching the log files.
Thank you for your help.
Kind regards,
Marc (Maliki)

Hello and please excuse the delay. I made test prints with gthumb and TurboPrint under several Ubuntu installations (23.04, 24.04 and 25.04) and could not reproduce this problem. For that reason I have no solution yet.

In your screenshots the page is always rotated and cut off in TurboPrint Monitor, no matter if you select "Portrait" or "Landscape" in gthumb - is this correct?