I created VF page and a lightning component, then embed VF Page to lightning component. Like follow code:
<iframe src="/apex/MyTestPage" width="100%" frameBorder="0" />
In Session Settings my settings as follow image
I set Whitelisted Domains as follow
When I use this lightning component in Lightning App Builder I got a gray screen and show refused to connect error.
May I ask help for how to resolved this issue.
Best wishes, Lee