Code Inspection: Naming rules are not applied deterministically

The code inspection step does not apply the naming rules described in CleanCode.sln.dotsettings according to a consistent scheme.
We have two rules specified but it seems that only one of them is getting applied.

Example: 

    <s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateInstanceFields/@EntryIndexedValue"><Policy Inspect="True" Prefix="m_" Suffix="Id" Style="AaBb_AaBb"><ExtraRule Prefix="m_" Suffix="" Style="AaBb_AaBb" /></Policy></s:String>
    <s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateStaticFields/@EntryIndexedValue"><Policy Inspect="True" Prefix="s_" Suffix="Id" Style="AaBb_AaBb"><ExtraRule Prefix="s_" Suffix="" Style="AaBb_AaBb" /></Policy></s:String>

With that Code:

[TestFixture]
   public class InspectionTest
   {
       private int m_Id = 15;
       private static int s_Id = 30;
       
       [Test]
       public void Then_it_should()
       {
           Assert.AreEqual(15, m_Id);
           Assert.AreEqual(30, s_Id);
       }
   }

We are getting the following Inspection-Errors:

Name 'm_Id' does not match rule 'Instance fields (private)'. Suggested name is 'm_'.

Name 's_Id' does not match rule 'Static fields (private)'. Suggested name is 's_'.

From our understanding, m_Id should be a valid name. After changing the field names to m_Idx and s_Idx, the inspection error disappears. If you then revert again, there will no longer be an inspection error. 
Please contact us for more information. How can this behavior be explained?