Lightmaps Not Working Cross Platform

Our build box is on a mac and artists are working on a pc. The lightmaps on various objects are coming out incorrect on mac but correct on pc (generated from platform).

I've seen several other posts talking about this being an issue that was resolved in 3.5, but we're on 3.5.2. We've tried reimporting and rebaking but still get this problem.

To get a release out the door, we're having to rebake on just the build machine, but what a PITA. Is there a planned fix for this (or an interim solution)? thanks, -Matt