Edit configuration form has problem loading & updating the sites entry

I currently realized that the site selection for the configurations has some problems.

I can create a new configuration linked to a site, but when I then open the edit page for the configuration again, it doesn't load the site entry that I assigned it to in the past.

After I change the site entry for the configuration & save, it seems that it still displays the name of the old site (but refers by link & id to the updated one).