Have you checked the settings between the Note 8 and the S8 are the same?
I've heard people having wi-fi issues when wi-fi assist is on (i think it's called wi-fi assist on iphone... I can't recall what they call it on Samsung, download booster maybe?).
It's a setting that allows you to bounce back and forth from Cellular and wi-fi, if your wi-fi is spotty.
You could try to reset the dash cam, just back up anything you want to save from your SD card first.
Plug your F800 in, power the vehicle up and wait for the cam to turn on.
Then hold the Mic button and the Record button for 5+ seconds, this should format the cam and hopefully you'll have some luck.
You should hear some voice notification/beeps to tell you when it's done.
