iPhone XR locked to owner

My iPhone XR was acting slow, so I try to completely power off. I held the power and volume buttons multiple times because the option to power off wasn’t showing. My passcode screen popped up and said face unlock wasn’t available. I know this is normal when you hold the power off buttons but don’t completely power off your phone. After powering off, I was able to power back on and got a screen telling me my iPhone had been updated. It asked me for my pass code and my passcode worked but after connecting to Wi-Fi I got the iPhone locked to owner screen.

On the iPhone locked to owner screen I see an email that starts with the same letter as my Apple ID email, but I’m certain the number of blank characters showing aren’t the same as my email. I tried using my phone number and as many passwords I could remember. Much to my horror I remembered that the last time I change my password, I use the recommended secure randomized password, which is only saved on my iPhone. I also saw an option to use my iPhone passcode to activate my phone. My pass code had worked initially to unlock my phone, but did not work to activate it.

I am the original owner of this phone. My phone was purchased by my mother as a gift when I was in high school from a Verizon store. Unless they sold us a returned phone, I’m not sure why the Apple ID or passcode would be different from mine. Is it possible someone has hacked my phone? I have the original box but unfortunately not the receipt. I am writing this from my iPad but unfortunately it has a different Apple ID so it hasn't been much help.

what steps can I take to activate or even reset my phone?

[Re-Titled by Moderator]