Synching Tracks Exported to Studio One 3 Professional

Hello. I am using Windows 7 and Audacity 2.1.0. I wish to export songs from Audacity to Studio One 3 (Professional), hereafter “S1,” using “export multiple” so that each track is exported separately. I wish to export the Audacity files as FLAC files into S1. In attempting to do this I have encountered a problem: the files do not remain in sync. This problem occurs even when silence is added to fill all vacant spaces between events on Audacity tracks prior to exporting. I assume I am doing something wrong and that there is a fix for this that is far easier than moving segments around in S1 until they line up as they do in Audacity.
QUESTION: How do I fix this so that the files remain in sync after transfer? Timestreching (or not) in S1 does not take care of this, and I think that could because some of the files exported from Audacity may be and are likely missing tempo markers or other information essential for timestretch to work. Sync-locking the tracks in Audacity makes no difference. I understand the difficulty and solution may lie in S1, not Audacity, and I am working on the problem from that direction as well.

Thanks in advance,

I meant to write "Timestreching (or not) in S1 does not take care of this, and I think that could be because … "

The problem is probably due to a “quirk” in Audacity.
If there is “empty space” at the start of the track, it is not included in the exported audio.
If different tracks have different amounts of empty space at the start, then the exported tracks will be out of sync when imported into another program (or even if they are imported back into Audacity). The workaround is to add a bit of “silence” at the start of each track - see this topic for more details: