Debugger Bug with large ScriptLibraries?

If have several ScriptLibraries of which two are vera large (about 1000 and 2000 lines of code). Since I work with Classes, all code is in the declaration section.When i change or create new functions or sub in the class and try to see what happens in the debugger, in one library the debugger does not show all lines of code, and in the other the debugger does not go the way it should (goes trough both if and else for example). In both cases, no error is triggered and nothing happens. Without the debug modus, the code is carried out as it should. But my problem is, that I can’t debug the code anymore.

Has anyone any Idea what the problem is? Is it a bug? Is it fixed in a later version? Is it a size problem?