Windows Network Share – How to Fix Slow File Opening in Large Directories

I have network share that contains several folders. One of those folders contains somewhere around 70,000 files, most of which are fairly small (less than 10kb) files, though some are significantly larger. The issue is that opening (via notepad or our own software) any one of the files in the folder, regardless of size, takes a good 30 seconds to a minute. Copying those same files happens at a normal speed. I tried moving a file to the root of the share, and the file opened instantly, which seems to rule out a networking issue. I also created a sub-directory inside the slow-to-load folder, and placed the file there. Again, the file opened promptly, so it should not be a permissions issue. I am assuming that there must be some process happening that is scanning all of the files in a folder each time a single file is loaded, but I am not sure what that process would be, or what I should look for.