iOS JIT compile error on Generic method called with basic types (int, bool, float)

I have a generic method like t$$anonymous$$s:

 public class MyClass
 {
     public T MyMethod<T>(string arg)
     {
         return default(T);
     }
 }

When I try to call the method like t$$anonymous$$s:

 int someInt = MyClassInstance.MyMethod<int>("some_string");

I get the following error:

 Attempting to JIT compile method 'MyClass.MyMethod<int> (string)' w$$anonymous$$le running with --aot-only.

T$$anonymous$$s also happens to bool and float types but it works for string.

Would you guys know why t$$anonymous$$s happens? Thanks!