# TexStudio autocompletion stopped working for macros

So I recently created macros (.sty files), which are remotely loaded at in my preamble. There are various points in these macros where I've defined a new command; for example:

\def\remark#1#{\definition{Remark \theremark\stepcounter{remark}{#1}}}


For another example:

\def\paren#1{\left(#1\right)}


This was all working very well, and TexStudio was recognising (and autocompleting) these definition. However, out of nowhere, this stopped working. Syntax highlighting is saying that it is wrong, and it won't autocomplete (however, it will still build and compile).

Does anyone know why this is the case? I don't really fancy making a .cwl file (mainly because I don't know how, but I'm sure I could figure it out if I had to). Any help would be greatly appreciated.

EDIT: I forgot to mention, but I have already made sure that I didn't accidentally turn off "Automatically load included files".

EDIT 2: I just created a new document with the same macros, and the macros are working on this, but still not working on the other documents I have... Strange.