Suddenly VOLTE not working on my moto g4 plus

I was using VOLTE services (from reliance jio in India) seamlessly since November 2016, but since June 2017 it suddenlt stopped working. I get an error "Unable to place call. Please try another method" while trying to make a call. I am able to access the internet and make/recieve calls from the Jio 4G Voice app. **UPDATES:** * I have enabled "enhanced 4G LTE mode" * Did a factory reset * My jio connection is on and working. Also, I can place/receive calls from the Jio4GVioce app which means the service is working fine.