According to the specifications listed on the T-Mobile website, there isn't a single CDMA radio in the T-Mobile model of the Note 8. So that is one strike against it. The LTE bands however do suggest that it might function as a VoLTE only device if you can load the right APN and VoLTE calls could be completed. Unfortunately there might be more to it than what I'm aware of and the phone model just isn't certified as a BYOD device for Verizon Wireless and can't be activated. Were you trying to activate the phone with a SIM card that was previously used in a Verizon Wireless branded device?
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.