We've got an extender at work since service is poor inside. For the longest time i connected and had full 4G service inside. But about 7 weeks ago i had 1x service and my phone was useless (this happened sometimes but only a day or 2) but i'm still having the same issue. I had the Pixel XL when this started and recently bought the LG V40, same issues.
Now today, i notice i'm connected to the extender again, though its going on and off, but even when its on and showing full 4G bars nothing will load or connect. It's like i still have no service. It's really, really annoying and i wish i had a fix.