As Stijn said, it works if you use an iframe and not the embed code. Here is the article with basic instructions:https://community.marketo.com/MarketoResource?id=kA650000000GuJJCA0
It seems very odd to me that Marketo cannot read the lead owner when it's a queue. This is clearly a Marketo bug that needs to be prioritized and fixed. I've worked with enough dev...