are these interpreted as square pixels PAR?
I attempted an image sequence of only two of they images instead of entire folder. Same result.
could you try to recreate this with some other Tiff images? see if this still happens? could you upload 2 of these images so I can test this on my system?
if this is urgent work I would import the files to Ae, drag them to a new composition icon, and create a sequence layers at composition in the project window 1 frame still duration
I have a vague reccolection of hearing about this issue, but don't recall the specifics.
I do a lot of time lapse work, but out of LR, not Bridge. Sometimes into Pr, but mostly into Ae. When I export from LR I always do a batch rename of the sequence starting the file name with a number, and never start with a zero, always a whole number.
And my notes say always import only from the Pull Down menu, at least in Pr. Then click on the first image and import as a sequence.
In LR you could select all and rotate the images , but I suspect it's an issue with your composition settings.
It sounds like something wrong in the sequence settings. I'd do a series of experiments.
try it in Pr,
try exporting and importing a small set as jpgs,
try changing composition settings,
try a different set of images,
rotate the images in Bridge (I assume you can)
If you have not tossed the last timelapse you made reopen that project and try to import the new images into that project as a new comp.
Just try one change at a time, there is a pony in there somewhere.