ConnectCore MP25 Yocto build fails

I have followed the instructions for native Linux.

Current DEY-5.0 (scarthgap branch) in use, no changes.
Build (all image types) fails on “No IMAGE_CMD defined for IMAGE_FSTYPES entry ‘stsplitpartitions’ “

ERROR: /usr/local/dey-5.0/sources/meta-openembedded/meta-multimedia/recipes-multimedia/images/meta-multimedia-image-all.bb: No IMAGE_CMD defined for IMAGE_FSTYPES entry ‘stsplitpartitions’ - possibly invalid type name or missing support class

Docker container build works just fine.

DEY-4.0 builds ok in the very same environment.

this question is worked by Digi Technical Support through your distributor.

Additional info
DEY 5.0-r2.2 works but DEY 5.0-r3.1 fails