QPluginLoader doesn't release plugin properly

Im trying to develop a hot loading for my qt plugins in my application. However I cannot release the .dll file of a formerly loaded plugin.

As an example I do the following:

//creating a plugin loader

QPluginLoader* loader = new QPluginLoader("C:\\someFolder
SomeQtPluginDll.dll");

//creating an instance

QObject* instance = loader->instance();

//lets assume I want do to hot loading here which means I have to release all instances of the plugin

delete instance;

loader->unload();

delete loader;

//now what happens is that I want to recompile my dll, but its not possible because the dll file is still locked by the application that is still running.

I also cannot not delete the dll in the file explorer manually.

Am I doing something wrong here or is this a bug in qt?