Yes, it looks like the upload server (or some other instance) can't properly process files above a file size of 500-600 MB. It doesn't matter if it's an image or a video. For me, there was always an error with larger file sizes in the last months, so the error should be easily reproducible with a simple larger file. Factors like dimensions or pixel count don't matter here, image sizes up to 65535x65535 (4.3 gigapixels: largest dimensions PNG supports), work.

That would be nice! :)

Thank you for you answers, I will upload a TAR.GZ archive and send the link within a few days :).

The file is quite large, 2,36 GiB at 26754 x 26754 pixels :). This size allows deep views of details in the image