I am currently having issues with how my version of lyx is handling math mode symbols. It is the same issue that is mentioned in this post "lyxminus" appearing in LyX however none of the fixes mentioned in the post work.
This issue started randomly today, with no alteration to lyx on my part.
I have already uninstalled my 2.3.1 version to get the up to date version (2.3.2) from the lyx home page however this has not fixed my issue. Please help.