When I try to apply a certain git stash in VS2019, I get an error saying there are uncommitted changes (there aren't) and only one file is applied

Running git status from my SourceTree terminal cleared up the error in Visual Studio. Even though the output of the command didn't show anything of interest:

$ git status
On branch develop
Your branch is up to date with 'origin/develop'.

nothing to commit, working tree clean

...but after doing that, Visual Studio let me apply the stash.