I've had decades of high end Samsung phone s with absolutely zero problems... S9+, earlier Notes etc. Frequent radio problems losing connectivity to 4G LTE, WIFI and Bluetooth issues. Bad antenna design or circuitry flaws. Had to already replace the entire mother board. I'll be damned if I need to follow their incessant fixes by restarting, turn off Wi-Fi calling, reset the network, replace SIM, factory reset suggestions etc, etc. What absolute gall and audacity. I bought the NOTE 20 predominately to keep the SD card feature from the S9+, rather than buy 512GB phone which can never be found. Time to escalate big time.
I had the entire Mother Board replaced with a new one plus new firmware flash and OS. Others have the same issue.
My guess, this is a serious design flaw in the antennas and/or circuitry and that Samsung well knows it.
You've already had it replaced twice and hasn't escalated??
if you'd like to add on to what's already been laid out, submit an error report for each of the mentioned issue to Samsung Members post observing the problem again. This will take it up to the engineers and if they don't find a fix it'll probably be taken up another level.
Thanks... I'll look into these signal apps. That's a great idea.
As far as taking the phone apart to check its antennas contacts, I could go back to Samsung as I'm not going to play with it. But, first I'll get the signal apps.