So I have upgraded from a Galaxy watch 3 LTE on EE in the UK, that ran on Tizen.
With this watch, as long as I was signed into my Samsung account on my watch and my phone, if I left my phone switched on at home and just had my watch, I would get my phone notifications pushed to my watch 95% of the time when I was in good 4G areas.
But my Galaxy watch 4 Classic LTE watch on EE, running on Google Wear is no where near as reliable. I would say most of the time, my watch is showing the phone symbol at the top, with a line through it, and my phone is stuck in 'Stand Alone' mode. I have great 4G signal. I can make and receive calls from watch, and use the data for downloading apps / Internet etc. But I can go hours without any phone notifications being pushed through. Other times, it works perfectly. There's no consistency.
It's like my phone is going into power save mode temporarily. I have even left my phone charging all day, with all powersave options turned off.
I believe the Watch 4 uses Google cloud based 'sync' - is it just a case that it's very unreliable?
I bought the LTE watch mainly so I could leave my phone at home and still get my notifications, but I can't rely on it, only for phone calls.
Just to add, watch works perfectly fine on Bluetooth, with no disconnections ever.
