I can't currently watch your video, because I'm traveling with limited internet only.
But since you are working with the test version of LRT, most likely you might have more images in Lightroom then you are processing in LRT, which you are obviously using in the free version.
To sort that out, I'd request you make a new folder (with a different name) - copy 400 images into that folder.
Remove the old folder from Lightroom, otherwise it might detect the images as duplicates.
Also check the notes on the "Install" page
https://lrtimelapse.com/install about the "Automatically write XMP data" setting, you need to turn that off in Lightroom.
Then follow the workflow once more on that new folder.
Start with "Metadata / Initialize" in LRTimelapse, since you might have edited that sequence before.
Take care of the basic advices of the tutorials and instructions
https://lrtimelapse.com/workflow - visual workflow - when editing.
When bringing this new sequence to Lightroom, it also should only show 400 images.
After using LRTExport for exporting, render the Video in LRTimelapse. It should show all of your edits.