Transferring files to/from windows file explorer

I’m running Nextcloud on a home NAS via unraid. (please keep in mind that I’m very new to all this networking/home server stuff). I noticed I can view everything that’s on my nextcloud in windows 10 file explorer. I can transfer files back and forth. If I upload a file through my nextcloud page on my PC or the mobile app, it appears in file explorer just as it should. But, if I do it in reverse, copy and paste a file from my PC or other device into a nextcloud folder via windows file explorer, it wont appear in nextcloud. How do I fix this?

How would Nextcloud know that? Nextcloud has to scan the file system for that.
You can use this command:

sudo -u www-data php occ files:scan --all


How do I use that command? Where do I type it in? What will it do?

All occ commands are run from the nextcloud folder on your server; usually /var/www/nextloud .

Without shell access (not recommended for you) you can use the app OCC Web and the short version of the command (but probably leads to more problems):
files:scan --all

I’m sorry, but I don’t know what any of that means. I don’t know what shell access or occ commands is and I certainly don’t want to do anything that will lead to more problems. If I add files to nextcloud, I can see it in the nextcloud directory in windows file explorer, but if I add files to the nextcloud directory in windows file explorer, I CANNOT see it in nextcloud. That doesn’t make sense to me.

The problem is the fact that Nextcloud does not scan automatically the whole directory. On change between the directorys Nextcloud uses database information and not the directory structure and in your case the database information is outdated.

But you can and should use on your Windows the Nextcloud client. Also if you use WebDAV on Windows the files are correct updated also in Nextcloud.

Which Nextcloud version do you use?
Perhaps it is solved in newer versions.
See issue.

Can you elaborate on this? Are you using Nextcloud desktop with/without virtual files, using a WebDAV mount, something else…?

Windows says the address that nextcloud gives me in settings to access files via webdav is invalid. Any ideas why???

WebDAV uses the network settings from Windows. Do you use e.g. a proxy? Try to access the url direct in Microsoft Edge. Please post the message from the browser.