Screen-based Visual Flow loaded in iFrame gives error reporting that Salesforce "refused to connect"

I’m not sure what is causing this issue. I have a button-launched Visual Flow that works just fine in Salesforce, but when I try to embed it into an iFrame within Skuid only the first screen seems to work. Here, I’m able to select a picklist value which should then send me to one of three screens based on my selection. Again, I am confident that the visual flow itself works as it works when launched from a Salesforce button.

However, when using it within an iFrame I don’t seem to be able to proceed to the next page. Each time I try, I get the following error message

Has any encountered this issue before? Does anyone have any troubleshooting tips?