Internal doorbell no longer works

Good morning,I have just purchased a **Ring video doorbell** and have just installed it. The Ring doorbell is working successfully but my internal digital doorbell doesn't chime any longer when the new bell push is pressed. When I installed the Ring device I tried the diode both ways round as recommended, but without success either way.My existing doorbell system is as follows:**A Honeywell series 9 DW915S digital doorbell with wired bell push and power from a low voltage transformer (Hager ST301 4VA 12v)**Can anyone offer any suggestions of what to try next?Thank you,Roger