I cannot connect Ring doorbell to my new router

I have a camera and a video doorbell. Both were connected and working fine. I have just changed my router - the camera connected to the new wifi network with no problems, but the doorbell will not connect. I have it right next to the router, and it keeps saying that there is either a problem with the internet connection, or it's too far away from the router. Neither of these things are correct. It's on 38% battery, so I am charging it, but I have tried 12 times now - both before and after connecting the camera. I will try again later in case the battery under half charge is the problem (baffling) but any other ideas welcome.