First frame not inserting correctly

I’m using the insert function to replace a phone screen that was shot practically but incorrectly.
I have three shots to do and out of the two that I’ve done, the track and insert work great on everything but the first frame. For one comp it’s just black, for another it links to a previous file that has been updated to include the correct phone number. Since it’s just a single frame I can patch them easily but would love to not have to go the extra step.

Are you using Standalone or Mocha Pro as a plugin inside a host?

Hello. I’m using it as a plugin inside Media Composer.

Are you importing the clip from disk via “Import…” or feeding it to the plugin from the Media Composer timeline via “Insert Layer”?

I’m using the import function inside mocha pro.
This is the technique I’m actually using Tutorial: Sign Replacement with mocha Pro. Align Surface and insert Module - YouTube

Thanks, and are these specifically single-image inserts (i.e TIF, JPG etc), or a clip file?

Single image inserts

Ok, that does seem odd, as single images should be consistent across the whole timeline.

Do you see the image the entire way through in Mocha, or is it a problem in both Mocha and the MC timeline?

If you’re seeing the problem directly in Mocha, there might be a problem with the frame offset.
Can you post an example of the problem frame in the Mocha GUI?