The Moto E6 sold for prepaid, has to be on prepaid for a while before it will work on postpaid.   When you purchased the new phone did you swap your Sim card from my old phone?  When you purchased the new phone did you swap your Sim card from my old phone? Or were you given a new Sim card to activate in the new phone?

how were you migrated from prepaid to postpaid service?   
https://www.verizon.com/smartphones/moto-e6-prepaid/