The automatic annotation of Terrain contours typically does not survive export in a format other than DGN, and in particular saving as DWG.
To overcome this, it is possible in a few steps to generate "fixed" contour annotation.
The procedure is as follows:
NOTE: all the steps can be automated by saving the commands in a VBA Macro.
Click on this link to download a DGNLIB that has an example linear Feature Definition definition "P_Courbe_de_Niveau_Annotation"
This last step is necessary to honor background masks:
Comparison with the original automatic annotations:
Printing from TrueView: Masks are honored:
Link to the DGNLIB: