Unexpected additional guide lines

[ygoe]

Here's a file in Visual Studio 2017 (15.3 preview 4). There are guide lines where there shouldn't be any.

The file is indented with tabs, each 2 columns wide.

After switching documents, the error has disappeared and lines are now normal again:

[ygoe]

I tend to find my own issues when I search for the general topic. Maybe this additional information is helpful: I've set up Visual Studio to indent tabs with 4 columns, but have overridden this for the current project and file type as per .editorconfig to only 2 columns. Maybe Indent Guides looks at the wrong place to read this information, or doesn't look often enough as it may change with every single document window now.