Yesterday I was traveling with my family in a rural area of my state. My iPhone XR indicated that I was on Extended Network and while I was able to make calls with four bars of signal, I was unable to use data at all. When I tried I received a "no network" message. My other family members were able to use data on older iPhones using physical SIMs.
When I dialed "*611" I was connected to US Cellular customer service rather than Verizon.
I check that the data was turned on and then reset the network settings, neither helped.
There are apparently still problems with the eSIm.