LPub3D - Submodel not shown in main model

[Jaco van der Molen]

Hi guys
After a long break, I work once again on a new building instrution for a MOC from a friend.
When adding submodels to the mainmodels, they are not shown in the main model.
This problem is on LPub3d - 2.3.6
Have download now the version 2.2.1, there is no problem.
Have anyone an idea?

Version 2.2.1:


Version 2.3.6:

Hmm, strange. Can you PM me the LDraw file? I'll take a look.