Failing assert in Hlt1Conf.persistency.mdf_write on v2-dbg platforms

A crash has been observed at !2907 (merged) in Hlt1Conf_persistency_mdf_write:

python3: ../Event/RecEvent/src/PrimaryVertices.cpp:129: LHCb::Event::PV::Chi2Accumulator LHCb::Event::PV::accumulate(ExtendedPrimaryVertex&, PVTracks&, float) [with bool UpdateWeightMatrix = true; bool UpdateWeight = true]: Assertion `none( ( abs( Vx ) <= std::numeric_limits<decltype( Vx )>::min() ) || abs( Vy ) <= std::numeric_limits<decltype( Vy )>::min() )' failed.
 *** Break *** abort

This error is triggered by assert at PrimaryVertices.cpp#L129

Observed only on v2-dbg platfroms (both DD4hep and DetDesc), no problem observed on v3 platform or regular v2 (both DD4hep and DetDesc).

Original comment: !2907 (comment 7797647)