How to pull a new submodule

Tried looking for answers on this site and others: StackOverflow - Easy way pull latest of all submodules

They all seem to want to talk about if you are controlling them, not if someone else added one, and I just want to pull the additional one into my project without having to stash or backup my changes if I need to delete the folder.

Should I delete the .gitmodules file, and/or the submodule directories that I have already pulled down with git clone --recursive? (StackOverflow - How to git clone including submodules?)

These commands do not seem to help either:

git submodule update --init --recursive seems like it did nothing.
git submodule update --recursive nothing.
git fetch --recurse-submodules output Fetching submodule ... several times.
git pull --recurse-submodules output the same thing, and then said Already up-to-date. after the fetch trial. Strange since in either case my submodules were already downloaded.
git clone --recursive ... Not tried yet. I feel like would overwrite any changes I have made, in the Stash or otherwise.
git submodule update --recursive --remote checked out a new commit SHA for one of the submodules.
git submodule update --recursive checked out a new commit SHA for one of the submodules. Could be the older, original commit level.
git submodule status gives the appropriate SHA, version, and name information for each, while still lacking the one that I want.
git submodule foreach git pull origin master
git submodule update does nothing.

I have been double-checking the library directory manually each time to make sure whether the additional submodule appeared or not.

I want to avoid performing certain actions, unless they are not destructive to my current repository state containing code changes, and solves my problem, in case it is a command I have mentioned but did not run, or anyone else has another to try.

I could try some of these with more effort, but I think I want to stop messing with them for now, and since I have not found the answer to this issue after doing some online searching, maybe the hopeful and eventual answer would help others anyway.

Am I suffering from the con mentioned here at all? Software Engineering - Git submodule vs Git clone