@Moem Great suggestion.
Since I am newbie, I did not think of this.
Also, I thought maybe I am doing something wrong.
Thank You

I deleted it after reading that Libertine is on its way out & Snap now supported, so I installed the snap version & it works OK- wireless external display - 4K TV.
Also connected $10 (USD-Amazon) Acasis USB-C port expander to charge and plug in USB Keyboard & USB stick (with *.ods test file).

@kugiigi said

I don't understand why they even care where you bought it. Unlocking bootloader factory resets the device right?
It's not like you're using it to access data from a stolen device..And you'll need access on the device to even allow unlocking

On my previous phone purchases (6 google Pixels, to install 5 LineageOS & 1 UT), I was aware I needed to buy 'Factory Unlocked', and not originally sold by Verizon or AT&T, because they refused to unlock bootloaders.
My guess is that, at least partly, they realize that by installing 3rd party firmware, we extend the life of the device and put off buying new ones.
I read what I could find regarding Oneplus, and it looked as though, as long as carrier was unlocked (which implied phone paid off), then Oneplus would unlock bootloader (for T-mobile sold models).
I discovered that, at least in my case (BE2028), not always true.
[Since this failure, I searched info for other possible UT candidates, and read that Xiaomi is less helpful for unlocking lately].
I also discovered (sadly for this UT project) there are far more 'factory unlocked' Pixels available used than Nord N10's !