I am on testing. I could isolate the problem causing code in the debian patches on file
drivers/iommu/intel/iommu.c With this changerolf@i7-5820K-debian-testing:~/kernel/linux-source-6.4/drivers/iommu/intel$ diff iommu.c.debian iommu.c
286c286 < int dmar_disabled = IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_OFF); --- > int dmar_disabled = !IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_ON); the problem is not there.