I had this EXACT same problem. I never did find out why and the Google searches didn't come up with a workable solution. So, after more searching, I found a work around. I created a Package with a copy of the SCCM imported drivers, added dpinst.exe with an XML file to do a recursive search of the folders. (https://msdn.microsoft.com/en-us/library/windows/hardware/ff544842%28v=vs.85%29.aspx)%C2'> Then in my OSD TS I created a command line step to use dpinst.exe (cmd /c dpinst.exe /S /SA /SE /SW /F) and referenced the created package. I did have to set the step to Continue on error.
I had this EXACT same problem. I never did find out why and the Google searches didn't come up with a workable solution. So, after more searching, I found a work around. I created a Package with a copy of the SCCM imported drivers, added dpinst.exe with an XML file to do a recursive search of the folders. (https://msdn.microsoft.com/en-us/library/windows/hardware/ff544842%28v=vs.85%29.aspx)%C2'> Then in my OSD TS I created a command line step to use dpinst.exe (cmd /c dpinst.exe /S /SA /SE /SW /F) and referenced the created package. I did have to set the step to Continue on error.