Trying a Note 5 again after 9 months, cell reception still horrible

[PAC757]

I bought a new Note 5 about 9 months ago, sold it because the cell signal was so weak. I thought I would buy another and a new SIM card from AT&T, same thing. Why can't Samsung make a phone with a decent antenna. I put the Sim card in my Nexus 6, worked fine, tried it in an Honor 8, worked fine. Using the LTE Discovery app here are the signal levels all at the same location and same time of day:
Nexus 6 = - 90db
Honor 8 = - 87db
Note 5 = - 109db
I have no complaints at all about my Note 5 other than the fact it's not reliable as a phone :/ but much more useful than the other 2 as I use this for a work phone. Going to try one last time to see if AT&T can be of any help. A co-worker suggested trying the Samsung help desk at Best Buy. Anyone else on AT&T have this problem?

 

[B. Diddy]

Do you have an AT&T Note5, or an unlocked one from a different carrier (or carrier-agnostic)? If it isn't an AT&T one, then perhaps the network bands it supports don't quite correspond to AT&T's strongest band.

 

[PAC757]

Do you have an AT&T Note5, or an unlocked one from a different carrier (or carrier-agnostic)? If it isn't an AT&T one, then perhaps the network bands it supports don't quite correspond to AT&T's strongest band.

Yes it's an AT&T Brand Note 5, this same thing happened with a Oneplus 3 kept trying to use Band 30. I noticed if I use any phone that doesn't have band 30 it works fine. I just assume it's the area I live in. I really don't know why AT&T uses band 30 as it has horrible / weak signal.