One of my phones downloaded the latest version and outbound calls stopped working over cellular data.
Outbound calls continued to work via WiFi connection, however.
I've gone through my phones and the latest version that seems to work for outbound calls over cellular data is version 20.00.842.0605
You should not update to version 20.01.864.0629.
You can get older versions from apkmirror.com (from the fine folks at AndroidPolice) or you can get version 20.00.842.0605 from my cloud drive at Chelle.biz.