Spectrum has nothing to do with Android version updates, they are just reselling service on Verizon's nationwide 4G LTE network. In order to receive the software update a phone has to be powered up on the Verizon network at the time the update is pushed out. If yours was sitting in Spectrum's warehouse inventory with no number assigned at that time, freshly updated software won't be sent until the new phone subscriber (YOU) request a version update using the menus on the phone.
Well, although it seems Verizon began rolling out the firmware update 2/1/2019, here it is 2/15/2019 and no update available....even though I am on my home's wifi 99% of the time.
So, I started the update manually, and it appears to be going through...Settings, Software Update, then the option at the top....don't remember what it is but it was above the AUTOMATIC UPDATE selection.
Version updating to G960USQU3CSAB/G960UOYN3CSAB/G960USQU3CSAB.
For the record, I do not understand mixing zero's and O's in any type of version sequence. Then again I don't expect a lot from SAMSUNG when it comes to software. Hardware is great, software is poor (at best).