Understand differences in VeloClusterTrackingSIMD between DetDesc and DD4Hep

Looking at this test: https://lhcb-nightlies.web.cern.ch/nightly/lhcb-dd4hep/1194/Panoptes/x86_64_v2-centos7-gcc11%2Bdd4hep-dbg/tests

VeloClusterTrackingSIMD gives different results depending if it is DD4Hep or DetDesc. This has to be understood.

In addition, the PV finding algorithms do not produce any tracks. Understand if this is related. Moore!1651 (merged)