Poor reception on my new Note 9.

If that doesn't work the Note is going back for exchange.
I doubt it's the phone, it's more like weak TMO coverage where you are. (Don't believe the maps, they're guestimates. There's a house near here in a totally solid coverage for Sprint, according to their maps. It sits just in the right spot behind a ridge that the signal skips right over the house. There's kinda-sorts reception from a single pane of glass in one upstairs window [probably picking up a reflection from something]. But the map says ...)

Try AT&T if you want GSM, on the basis of a 24 hour trial and no charge if there's no signal.

(The first choice in cellphones is coverage. If you get the greatest cellphone ever invented, for free, with no monthly charge - and live in an area that gets poor coverage, the phone is basically useless to you. Choose your carrier by coverage. Choose your plan for that carrier based on your needs. Then choose your phone.)
 
Well it looks like I'm heading back to Verizon. Took the phone back to T-Mobile to try out a new sim card. No change, still one to two bars. Got a line from a sales person that the basic Samsung unlocked phones don't play well with T-Mobile. Exchanged the phone at Best Buy. New phone gets the same reception.
 
I would suggest getting the T-mobile branded model. I previously had an unlocked phone I had purchased from B&H and it was supposed to have had all of the main T-mobile bands but after experiencing connectivity issues and dropped calls I was advised that T-mobile has their Volte configured in a way that causes problems for some non-Tmo variants. On that unlocked device I also could not use Wi-Fi calling and missed the majority of software/security updates. Oh, and I'm in CBus.
 
I would suggest getting the T-mobile branded model. I previously had an unlocked phone I had purchased from B&H and it was supposed to have had all of the main T-mobile bands but after experiencing connectivity issues and dropped calls I was advised that T-mobile has their Volte configured in a way that causes problems for some non-Tmo variants. On that unlocked device I also could not use Wi-Fi calling and missed the majority of software/security updates. Oh, and I'm in CBus.
I'm going to drive around the city to get an idea what kind of reception I get with the new phone. I could be in a reduced coverage area at my house. If the general reception still sucks, I'm off to Big Red. Later on I may let my son flash a Verizon image to this phone to resolve the WIFI calling issue with unlocked non-Verizon phones.
 
Tried several locations around town. As you might expect I had varying degrees of success. Unfortunately, although reception was good in some areas, two out of four bars was common. Final stop was at a Verizon store where I switched service to Big Red. I realize I'll be giving up WIFI calling, but I'll trade that for better reception. Thanks everyone for all the advice. In the future I'll stick to carrier-branded phones.
 
Finally added signal strength software to all my household cell phones. Turns out I must live in the Black Hole of Calcutta. Pulling -101dB on my Pixel 2XL, 99 on my Note 9, and 92 on my Moto X4 (all on Verizon). I knew trying to compare bars was not ideal since there's no uniformity between manufacturers, but still getting a stronger signal than what I got on T-Mobile.
 
Not like you guys living over the pond where the reception problems must be a pain, we live in a village in the sticks of East Yorkshire in the UK. Cellular reception is pretty crap out here but thanks to EE we have a fantastic WiFi calling.
 
Pretty crappy here - Swisscom, Switzerland. Got great reception with the Pixel 3XL. Wonder if the note9 just doesn't support the LTE band they use here (no, it's not an imported device)