Daycare eventually tracked down the issue on this. It was a result of bad interactions between AEM, a modern browser, and the touchscreen API on Windows 10 laptops. A workaround for Chrome is to turn off the touchscreen API.
Hi Scott, my colleague was able to get this working on an instance with SP1, CFP3, ACS3.9, without the Forms Add-On. I'm now going to try to replicate this exact combination. The only remaining difference would be that I'm on Windows while he is on MacOS.
There is an issue with your instance. To see this work the way its suppose to work - try on a fresh instance. Copy the Qucik Start JAR to a new folder and start again. Then try again - to see it working successfully.
For you current AEM Server - looks like you loaded a package that is causing an issue.