I heard that if a component is not attached tight enough in the Note10, there can be weak signal issues. This was from a teardown I saw somewhere.
Samsung doesn't test for proper signal connection according to what I see in the diagnostics TESTMODE.
Problems are back with mine as well. I thought switching carriers was the solution but all issues are back with cellular reception. The note 8 didn't have that great of cell service but the Note 10+ makes the note 8 look superior in reception.
I've had my phone T-Mobile Note 10 plus for 3 days. Switched SIM card from a Galaxy 8, no signal problems at all. WARNING!! DId have an issue with S-Pen. Purchased wallet case w/magnet strip for closing. Completely disrupts S-pen blue tooth. Also phone does not operate properly. Took out of wallet, perfect. Spread the word, this was also on the samsung troubleshooting help page. Awesome phone!!.
I have the exact same problem with an unlocked Note 10+ on ATT. My previous phone the galaxy s9+ had great signal at my house and this new note 10+ gets zero or 1 bar at my house. My house is less than a mile from a LTE cell tower too.
Same, also have issues on T-Mobile. Pixel 3 gives me solid signal and Note 10 goes out of service, can't even make a call. I think it's not connecting to the same band that Pixel does