Black Gaps Appear between some clips after exporting

So, I'nm working on a small 1 min project. I've processed it out a few times, without issue, each time, changing the cut a little. This last time, on what what I expected to be my final cut, there's gaps between some clips. I went into the timeline to make sure there's no spaces between them and there's not. I even went as far as putting clips on separate layers and overlapping them and I still get gaps. They're super short, but obviously noticeable. Can someone help? This is a paid gig and I'm trying to get an edit in tomorrow.

Side note, I added a grain layer over the top, and when layer is activate for export, you see the grain in between the clips. When I deactivate the grain layer, the gaps are black.

Thanks in advance