Why does visual studio mark all new classes as <Compile Remove /> in my csproj file?

Whenever I add a new class to my project, visual studio adds and entry for it in the csproj file with
<Compile Remove="<folder_path>\file.cs" />

How can I stop it from doing that?

I have to go in and delete that entry for each file I add.

I have tried to set EnableDefaultCompileItems and EnableDefaultItems but those don't seem to fix this problem.

I have added some items in the csproj file as <Content Include and I'm wondering if that is triggering Visual Studio to remove anything new I add.