Apple Watch auto-answer feature stops

I have an Apple Watch that is set up on my phone with family sharing. It is for my demented father and I have set it up to auto answer but it only auto answered a couple of times and then is stops. Can someone help me fix this? I have turned auto answer off and back on (that sometimes works for one go) I have turned the phones and watches off and back on and I have un paired the watch and re paired it a couple of times and it still does not work. It used to work about a year ago and then it started to glitch. I have also completed all the updates.