New Pro 2 Hot On Plug-in Adapter 2nd Gen

I have a brand new Ring Pro 2 Video Doorbell.I have not installed it into my doorbell wiring yet. It is inside my home lying on a table. Room temperature is 74 degrees Fahrenheit.I am trying it out by hooking it up to the Ring Plug-in Adapter 2nd Generation.I notice that the Video Doorbell unit gets very hot.Is this normal ???Also, the Pro 2 Video Doorbell is intended for 24 VAC.But the logo on the back of the Ring Plug-in Adapter 2nd Generation shows 24 V with the symbol for DC a solid line above a dashed line.So after all the literature saying use AC only, why is Ring's Plug-in Adapter show a marking for DC output?