Plug in adapter

Hello, i have been installing quite a few door bell in past few years A second video door bell pro failed at one customer. The first one lost wifi connection. Did troubleshoot, door bell started to act weird. Call tech support, replaced door bell. Second door bell lasted a day and lost wifi too. Even the app shows -55db signal level. The door bell pro is powered by the plug in adapter gen 2. I noticed that now the plug in adapter shows 24VDC. The ring door bell pro requires 16-24 V AC. Speaking to tech support, she said no the door bell pro requires AC voltage. At first she said door bell need 16-24 Ghz. ???? Try to get info if there is another AC plug in adapter but she could not help me. Second phone call, agent took note and said indeed this is weird and transfer me to higher level. Then 3rd agent wanted to get pic of the plug in adapter and pics of the wires at the door bell. And also wanted to get customer on the line to authorize her to help me. Well customer had left already. Normally ring send an email or text to customer to authorize troubleshooting but that time the agent wanted to speak to customer directly. Can anyone help me? Why plug in deliver DC voltage? Why ring tech support ( 3 diff agent) insists that door bell pro needs AC voltage? Or should work and just a coincidence that 2 video door bell pro goes bad. I would greatly appreciate some help. Thank you in advance