1803 breaks network drives?

Here's something that forced a rollback from the Windows 10 version 1803 update. After installing the update, I could no longer write to or reach a USB flash drive that was being used as a network drive through a Linksys router. All attempts to solve this failed, and Microsoft level two support could not find a solution. The only way out was to roll back to version 1709. Right now, this is an unsolvable problem, and that evaluation comes from Microsoft support. You may want to check for similar trouble after installing version 1803.

The 1809 update changed how the shared resources are connected, when compared to 1803 version. I'd like to say that 1809 is the same as it had been in 1709, but I have not finished testing it yet.

You should look at the excellent tutorial how to share resources in Windows 10, especially, if you're having issues:

Share Files and Folders Over a Network in Windows 10 | Windows 10 Tutorials

PS: I've updated my system last week to 1803 and the system had similar issues as yours. That issue seem to disappeared, when my PC accidentally updated to version 1809, forgot to set the policy of delaying feature updates...

I haven't had any sharing problems with Windows 10, regardless of version (every version since 1703 (or 1704?).
So I wonder why some people have problems and others do not.

I create shares with "net use X: \\host\C password /user user-name /persistent:yes"
Is that why mine always works?