Just to add some more verbiage to this mess - I sent a Pixel 3a XL in to sell, not as a trade in on the Note 10 - The site I sent it to gave me the same not reset properly talk since my account was still on the phone.
(I think I mentioned all this previously)
I called and talked to a tech and he said that Google, with out telling anybody, had changed the reset procedure and accounts were not being erased. The phone was returned to me and sure enough, my Google acct was still on the phone. Like you, this wasn't my 1st rodeo, and I know that factory rest/erase all data/blah/blah/blah. I went in and removed the account, reset it again, made sure the account was gone, sent the phone back and my check is in the mail.
You sent a Pixel, I sent a Pixel - I'm not sure Samsung is to blame in this situation - seems to me the issue is with Google/Pixel. I don't know if anybody else has had this issue with any other phones - just sayin'
While I don't have a house full of Samsung products as you do, I have purchased enough Samsung SSDs to supply a small 4th world country, and been happy with all of them.
As far as dealing with the Cust Serv Reps, most companies have a "system" - and God forbid you try to ask about, or do anything that falls outside the system. Several years ago I bought something on line from Macy's, it never arrived, called them and they issued me a credit. A few days go by and the package shows up on a porch I wasn't expecting it to be on. I call Macy's, tell them I finally found the package and I owe them the money for the shirts. Rep says " you mean to tell me you are calling to tell us you owe us money" I said "yep" - she says "hold on". Comes back on the phone and tells me their system is not set up charge under these conditions and I was to enjoy the shirts on them.
what has been learned here:
I have way to much time on my hands
I am an honest person
Never mess with "the System"
AND
Offering you a $25.00 gift certificate to buy more stuff from someone you are complaining about is a "system" thing, not a "person" thing.
I feel a lot better now.