Unsolved QtLocation Plugin problem

[Xeyos]

Hi everyone,
i am trying to implement my own plugin and i based on this:
https://github.com/vladest/Bing (which is simple and seemed to suit me)

But I ran into a bug that I can't solve.

I tried to use my plugin with the present example "mapviewer" and I saw that trying to change the map the active one always remains the same.
I noticed that this problem also occurs with the Bing plugin, but no with the others plugin. So the problem is on plugin, but i didn't found it.

Some suggest?