Lights always need to be rotated by 90 degrees
OpenMW currently applied a 90 degree rotation to meshes with a BoneOffset node. https://gitlab.com/OpenMW/openmw/-/blob/master/components/sceneutil/attach.cpp#L145
Morrowind.exe appears to only support BoneOffsets for lights (it didn't work for weapons and shields at least) and carryable always appear to have this node. However, it applies the 90 degree rotation to all lights regardless of the presence of a BoneOffset.
The pipes in this mod don't have a BoneOffet node and therefore have the wrong rotation in OpenMW https://www.nexusmods.com/morrowind/mods/22788