Today I also installed the June security path update. After update...I'm also facing the same problem. I've two Sims Jio and Airtel . Both were volte networks. And I used to see volte symbols for both of them. Now neither of them are showing. Volte is not working. Even though the option in the settings is enabled about "Enhanced 4g LTE mode" for both of them, but neither of them are using volte anymore. I'm not able to make phone calls and receive calls. Please solve the problem as soon as possible....and moreover next time onwards try to verify the updates for any possible bugs before releasing them as we're not beta testing users.