We’ve seen this issue come up once before. It mainly seems to be related to a scenario where images are labeled in sequence (image01.jpg, image02.jpg, etc.), and the import option in After Effects that reads “ImporterJPEG Sequence” is enabled. Let me lay out what we encountered previously, and hopefully, that will give you some insight into what’s happening here.
So there are two scenarios that we’ve seen that could explain this. The first is when an image is imported into After Effects with the “ImporterJPEG Sequence” checked. This creates an asset that’s a JPEG sequence instead of a static image. When this asset is dropped into the timeline, it reads as a single-frame media file as opposed to a JPEG. This causes the layer to shrink to one frame whenever the first image in the sequence is loaded. In this scenario, cycling through the Templater data to image02, image03, etc., causes the layer to revert to a static image since those other images aren’t read as a JPEG sequence.
In the alternate scenario, the project already uses image01, and the JPEG sequence is imported after the fact. In this case, Templater will check the project file for image01 when it’s loaded, find the JPEG sequence, and then swap it in, causing the layer to be switched with the 1-frame media file.
The easiest way to fix this issue is to search your project for any JPEG sequences that are present and then right-click and choose Replace Footage>File. From there, you’ll want to select the appropriate image file and ensure that the “ImporterJPEG Sequence” option is unchecked. This should replace the sequence with a static image, which should keep this from occurring in the future.
Hopefully, that’s all that this is, but if you run into any difficulties or this doesn’t fix the problem, please feel free to let us know, and we’ll see where we need to go from there.