I’ve got an mix with 45m25s, added 18 labels and exported them with “Export Multiple”, “Split Files based on labels”. It sounded not clean when I listen to them as one mix again. For a test, i merged the 18 tracks again and only got 45mh17s, 7 seconds were missing.
Is this a common problem? I use Win 10, 64 bit and Audacity 3.0.0.
Observe final track ends dead on the 3 minute mark
Note that I used point labels starting at T=0 and thus no audfio is excluded from the export multiple.
I suspect that you were using range labels with a small gap or gaps between some of the audio.