That's actually really common with 5G. Try standing directly underneath a 5G tower. That's when you'll really see it difference. I mean, it's a less crowded Network so it's faster anyway. But 5G is pretty bad through walls or even windows. Bad compared to being right next to the tower. It's still better than LTE.
One thing to check, if you haven't ... some folks have missed this setting ... check the screenshot ...
Same here. At first is wasn't working then I removed all Facebook related apps and it started working for a couple days. Now its back to not working. 5G it says sim card unknown ( even tho I have full bars) but 4G everything works as it should. Im on TMobile
You should try getting the esim activate it on tmobile, it might make a difference. Getting good speeds, speed test shows lte on the test, but not sure if lte signals can achieve that