Chime Pro not ringing and cannot test sounds on APP

I have a Ring door bell and chime pro which was working correctly. recently, I noticed that only the ring doorbell was ring when used and that the chime was silent. I checked the app settings and the chime is linked to the doorbell and both notification sounds are ticked as active.I have switched off the WIFI router, reloaded the app, reset both the doorbell and chime pro. The APP says both items are working fine and no issues. However, no matter what I do I cannot get the chime to both test chimes or make noise when the door bell is used. Please help!