I don't think it is that my colleague edited the document to be like this, or inadvertently added a paragraph mark after the footnote. The reason for my belief is that he copy-pasted his version of the file onto a flash drive, and I then took the flash drive and opened that very file on my computer. The paragraph mark is not present when I open the file in my computer. So by this we know it is the exact same file we are comparing, and not two different versions of the file. The same file when opened on his computer show the paragraph mark, and when opened on my computer it does not.

So perhaps it is that his MS Word 2019 has become corrupted in some way?

I'll just mention here, although I don't think this should account for the difference: His computer is an imac, and he has parallels installed on it, and within parallels he is running Word 2019. But so far as I know, Parallels accurately reproduces the native Windows environment, and if that is the case then using Word in Parallels should not create any such change in the file when opening it.

As for the language version of Windows and Word, as per my understanding we are both using the English language version of the software. I have personally set up the Hindi language on both computers, and that too only for typing; we do not have Hindi set up to be the language of the OS or of the Word program in either computer.