Have you enabled #VoLTE on your Pixel yet? If not, then you're not taking full advantage of the Sprint network and your Pixel 4/4XL device.
VoLTE is now available to a number of Sprint phones, and in most Sprint coverage areas. You can use VoLTE in conjunction with WiFi Calling. Your calls should "hand off" between WiFi and VoLTE seamlessly when one network is weaker and the other is stronger.
Start by enabling VoLTE on your Pixel 4/4XL: Settings > Network & Internet > Mobile Network : Enable the VoLTE option.
You're all set! Now you can talk and surf at the same time.
I ran through a few test calls today (7 Feb, 2020) to check my data throughput. I was fairly pleased with the results, given I was working inside an office building. I was able to check my social apps, run through a few emails, and I even ran a couple of Ookla Speedtest sessions all while connected on a VoLTE voice call running simultaneously.
This is a feature that has been a LONG time coming for our Sprint customers. I'm happy to be able to "flip this switch" and experience VoLTE! I hope you are too.
If you enable VoLTE on your Sprint Pixel 4/4XL your data allotment will not be impacted by VoLTE calls. But, anything data related that you do while you're on a VoLTE call will deficit your monthly data allotment.
I'll report back if I encounter any issues or "gotchas." Understand that like any wireless service, geographic, coverage, and radio interference can impact your experience.
Disclaimer: The Product Ambassadors are Sprint employees from many different parts of the company that love technology. They volunteer to test out all sorts of Sprint devices and offer opinions freely to the Community. Each Product Ambassador shares their own opinions of these devices, therefore the information in this post does not necessarily reflect the opinions of Sprint. The PA's do not represent the company in an official way, and should not be expected to respond to Community members in an official capacity. #sprintemployee