QGIS OTB Toolbox Mosaic - Cutlines don't work

QGIS version: 3.30.3

I have 6 color geotiffs that overlap. I have drawn overlapping polygons excluding photo are I would like to exclude in the Mosaic process.
I include the 6 polygons in the Mosaic process but the process fails. I have tried polygons with coincident boundaries and also polygons that overlap. The result is the same. Failure.
Not sure how the cutlines are to be applied but the documentation does not explain anything about them really.

Dear @Mikester-Calgary,

Thank you for using OTB!

Could you share the log that QGIS provides?

Julien Osman.