Skipping Rests When Exporting to Audio File

[videogame_munkey]

I'm trying to export a drum track to a .wav file, but every time there's a long enough rest, it skips the silence completely, although during the recording process, it looks like it goes through the track normally. It also seems to skip at more random times that I don't quite understand, where it would be much more difficult and tedious to just slice and add a pause in an audio editing software. I have not had this problem until very recently. No such problem when exporting all the instruments at once, only when one at a time. The same issue occurs while exporting to mp3. If this is some result of how the exporting process works, it's a fairly catastrophic oversight, as obviously silence is an important part of music.

Edit: Also it's not only the 2013 drums instrument that has this problem, it's other instruments too.