Footnotes mess up main body formatting when compiling

I’ve been having problems when compiling my work, which includes a good number of footnotes, in .docx or .pdf files. In both .docx and .pdf files, some of the main body of the text immediately following some of the superscript footnote numbers is italicised. Sometimes just one or two lines is italicised, sometimes it is entire pages. Further, in .docx files, the text of the footnote itself is moved to the main body and is placed in superscript immediately following the superscript footnote number. The footnote is blank. The main body text then continues in superscript, sometimes also italicised, for anywhere between a couple of lines and half a page.

I am at a complete loss as to why this is happening, so any help would be greatly appreciated!