Kudos to Planet Computers! They responded to my support questions on this topic in hours (considering the time difference, even more remarkable)!
Here is the reply which I received from Eric:
"To enable 4G LTE, you should navigate to the Settings - More (under Wireless & networks) - Mobile networks and enable Enhanced 4G LTE Mode. This would also be affected based on coverage around your area.
You can check if your Gemini has eSIM by looking at the back of its box. If it has 2 IMEI numbers listed, then it would have the eSIM module. If there is only one IMEI number and empty space after it, then that would be an X25 model which doesn't have the eSIM chip."
So the "enable Enhanced 4G LTE mode" is on and the wi-fi is off and I am having no problem streaming 4K videos. (I have excellent AT&T mobile coverage in my area).
One cautionary note from the company for us in the USA on the use of the eSIM capability "LTE works on both the eSIM and the removable SIM card module. However, you might currently still struggle finding a consumer carrier network which supports eSIM. It's a very new standard that most carriers still haven't made public."
I commend Planet computers on the speed of their support replies.
