High Voltage Ring Wired

I originally set up my transformer at 24v, and the Device Health section of the app said the voltage is at 39v and is too high. So I set the voltage to 16v, and checked it with a multimeter. It says there is 18.7v coming from the transformer, yet the Ring app is still saying there is 39v. The voltage from the wires that I connected to the Ring device corresponded with the reading I got from the transformer, so why is it reading 39v? Anyone out there have this problem? I am using a Hampton Bay transformer. The Ring app is trying to get me to purchase a Ring transformer. Maybe this is just a marketing technique? Thank you for your help.