Video battery doorbell not activating mechanical chime

Battery Video doorbell Gen 3 wont operate existing mechanical chime when operating with battery installed(hardwired to AC from previous doorbell).

It works fine apart from this ( Motion detection, doorbell , video , links to alexa echo show etc.) .
18v Ac supply verified.
Reset to factory defaults more than once etc.

Whats odd is that if i remove the battery from the Gen 3 and then press the doorbell the mechanical chime works.

But then I don’t have any ring application functionality as without the battery its a dumb terminal.

Any ideas?

All input appreciated.

Ps. Some posts mention an in app option under device settings where you can select chime ( mechanical or electronic etc) . I cannot this. Has this option been removed?

Hi @user36187. What is the make and model of your mechanical chime kit? Not all chime kits are compatible with every Ring Doorbell, so this may be the problem. You can find a list of chime kits that our teams have tested here to see if yours is under the compatible or incompatible list. The chime option in the Ring app you mentioned is for the Video Doorbell Pro, which is one of our hardwired Doorbells.