data secured

ok, but which documents folder, and where actually is it?

Because if you have onedrive installed then that does not sync your documents folder. It syncs its own folder that it puts god knows where. And then does its best to have explorer open its folder instead of your documents folder. Which does not always work. So sometimes you get an app that actually opens "c:/users/username/documents" and it'll be empty

If you have the option to sync documents folder with onedrive, its the same one.
If you don’t, I’m assuming the autosave with cloud enabled will save it in a different documents folder inside onedrive folder. This onedrive folder is by default in your user folder, but you should have quick access to it in the list of folder on the left of the explorer window, or by double clicking on the onedrive icon in the taskbar.
The only time it can be tricky to locate these files is when the app closes unexpectedly (for whatever reason), and you have to try to locate the .tmp file in the appdata.
Otherwise, the only chance your file is somewhere else is if you edit an existing file or if you save it in another location by mistake. This is easily solved by checking the latest saved files.
It’s not as tricky as you’re trying to make it out to be
- The only way I can get to my actual, local, documents folder is to go directly through my home folder.
  and the only way to get to that is through c:/users, because microsoft keep doing their best to hide that a home folder exists.
  I'm not speculating. this is what happens on the machine I use daily.
  click my documents in the sidebar. then install onedrive and press the same button. it takes you somewhere else. where your files aren't
  
  The local documents folder is always by default in the list of pinned folders, the ones I mentioned in the last reply. On the left side of the explorer.
  In alternative, you can go to your users folder and create a shortcut in your desktop, or another location of your choice; create a shortcut for each subfolder of your choice in your desktop, or another location of your choice; or pin them in the list mentioned previously. Customize your machine to your personal preference.
  I’m also speaking from personal experience, I work with Excel almost daily. Perhaps try to understand how you have your onedrive configured. Or if you don’t use it, just uninstall it and/or don’t use the autosave with cloud feature
  
  I know it is always there by default, unless you install onedrive. Then that same button gets repurposed and it doesn't point to your local documents directory anymore. You don't get two documents shortcuts. like you, I also use my computer daily. that's nothing special. most people do
  
  It doesn’t point you to a different folder, it’s the same directory as the local Documents.
  What I suggested is that you could create your own shortcuts that fit better your needs, I didn’t say it would create two documents shortcuts. I’m not sure what you are talking about.
  And hey, I was trying to give you tips on how things actually work. If you want to be antagonistic, fine, I’ll shut up then 🤐
  Have a good one
  
  It is not. if it were, they'd both contain the same files. they do not. so they're not.
  They'd also have the same directory path. They do not. Going to those two different paths gives you a different set of files.
  I just scanned the files in both directories. the files in them are physically on different spots on the filesystem, at the cluster level.
  They are not the same directory. I don't know what to tell you.
  
  C:\usersuser}\documents is the windows default
  Onedrivechanges it to C:\usersuser}\onedrive\documents
  I believe this is the 'known folder move' feature. I kinda assumed it does the same sort of thing for desktop, did you get bitten in that front, too?

Sometimes it's the last folder you saved to. Sometimes it's OneDrive. Word these days really likes to push you to OneDrive or other MS services, it takes effort to save where you want.

It’s the last folder you saved to if you’re still using the office app after saving the last file, otherwise it will fall back to Documents.

Not always.