I haven't run into this problem by myself. I know I've been confused previously by the different "explode" settings, though. If you haven't done that already, I'd test them all and see if something changes.
Also, there's a text about label conversion on the AchicadWiki:
http://www.archicadwiki.com/TechNotes/DWG_label-leader_conversion_in_PM?highlight=%28DWG%29
I don't think it's fully clear, though. It concentrates more on appearance than functionality.
Of course, if you've tested all options, and you are certain of what this is pn the Autcad side, it might be a bug in the translator. If you think that, you should contact your reseller and let them forward your bug report to Graphiisoft.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1