If class InnerAnnon is instanciated, type annotations on ia_m1() are incorrectly written to classfile.
They are all written as Runtime(In)VisibleAnnotations,

    RuntimeVisibleAnnotations:
      0: #16()
      1: #17()
    RuntimeInvisibleAnnotations:
      0: #19()
      1: #20()

If the declaration for IA is commented out, they are written as expected:
    RuntimeVisibleAnnotations:
      0: #16()
    RuntimeInvisibleAnnotations:
      0: #18()
    RuntimeVisibleTypeAnnotations:
      0: #20(): METHOD_RETURN
      1: #16(): METHOD_RETURN
    RuntimeInvisibleTypeAnnotations:
      0: #22(): METHOD_RETURN
      1: #18(): METHOD_RETURN

Compile this as Test1.java and run javap -v Test1$1$InnerAnon

import java.lang.annotation.*;
import static java.lang.annotation.RetentionPolicy.*;
import static java.lang.annotation.ElementType.*;
import java.util.List;

class Test1<T> {
    Object mtest( Test1<T> t){ return null; }
    Object mmtest( Test1<T> t){ return null; }

    public void test() {
 
        mtest( new Test1<T>() {
                class InnerAnon<U> { // Test1$1$InnerAnon.class
                    @A @B @C @D String ia_m1(){ return null; };
                }
    //If this is commented out, annotations are attributed correctly
                InnerAnon<String> IA = new InnerAnon< String>();
           });
   }
}

@Retention(RUNTIME) @Target({TYPE_USE,FIELD}) @interface A { }
@Retention(RUNTIME) @Target({TYPE_USE,METHOD}) @interface B { }
@Retention(CLASS) @Target({TYPE_USE,FIELD}) @interface C { }
@Retention(CLASS) @Target({TYPE_USE,METHOD}) @interface D { }