Apple Watch Not Vibrating for Calls- all other vibrations work

My watch will not vibrate for phone calls. The watch is on silent (as is my phone with no vibration as I can’t have it ring at work.

It used to work perfectly fine, now all of a sudden I miss calls because my watch has stopped vibrating. All other notifications vibrate.

I went so far as to reset my watch- that worked for a few days, now it’s doing the same thing again.

Help!