Thank you for your reply. HD calling is enabled on my account. I'm using the stock ROM and can verify voice over LTE does, in fact, work. I can live without Wi-Fi calling but without voice over LTE, I can't use data while I'm on a phone call, not to mention the quality of the voice call is much lower. Therefore, it's very important to me this feature be implemented.It does not work on either of my 6Ps and I am also on Verizon. Unlocked or "Non-Verizon" phones can be a pain on their network. I am about to leave Verizon for T-Mobile or AT&T even though I travel a lot and use a lot of data (still on a grandfathered unlimited data plan). I am tired of Verizon and their restrictive policies. I also have an Essential Phone, and Verizon won't allow it to use Wi-Fi calling. It works fine on my business T-Mobile plan. I don't remember if VoLTE worked on the stock 6p ROM with Verizon as that has been a long time ago. I just recently switched back to my 6p when my Pixel XL died. The only thing I can tell you is to make sure HD calling is turned on in your Verizon account (It should be already). You can try calling a Verizon CS, but I can tell you from experience, they will not be much help. Good luck.