IDE0051 false positive, all private members are shown as unused (light grey font color)

[cremor]

Version Used: Visual Studio 17.12.4

Steps to Reproduce:
I don't know how to reproduce it. But I can share the following information:

• It seems to mostly happen when I start or stop debugging my application.
• It also happens when I close a Git compare window of a file (which switches back to the normal view of the file).
• This is in a big .NET Framework 4.8 WPF solution. I don't know yet if this can also happen with other target frameworks.
• It only affects private instance members. Static members and members that are partial themselves are not affected.
• When it happens then all of the private instance members of the file are affected.
• It might be that this only affects members in partial classes. The usage is in the same partial (same file).
• I only noticed this problem after I updated from VS 17.12.3 to 17.12.4, so it might be a new bug in 17.12.4.

Diagnostic Id: "IDE0051: Remove unused private member"

Expected Behavior:
Used private members should not be shown as unused.

Actual Behavior:
Used private members show IDE0051 and are shown in light grey font color.
Sometimes the problem automatically fixes itself when I stop debugging.
It always fixes itself when I hit F6 to compile the solution.

As you can see in this screenshot, it even shows the reference above the member, but still shows IDE0051: