I did the Webbuttons embedded in WebContainer embedded in other WebContainer and I was able to click on one and the action event fired without issues.
I can't resize the WebContainer within another WebContainer, but the single WebContainer with the embedded buttons work as expected when I resize. Don't know if it is a bug or is not valid to put a WebContainer inside another WebContainer.
If you have a sample of your code to show the WebButtons not receiving the events, please share it so others can take a look.
Edit: You can move the topic to Targets - Web too