Activation Lock status issue on my MacBook Pro

Hi everyone, I just upgraded from Intel-based MacBook Pro 13inch 2017 core i5 to a brand new M4 MacBook Pro 14inch on this Monday (I bought online & picked up at Apple Store). After unboxed, I went through set up process and created standard user then reset like system's recommendation to make it work. It's reboot normal until I login to user admin then the Finder window was stuck on desktop. I had to use force quit to close all windows. When I reopened Finder, clicked on a folder, its keep flashing and lag. I called Apple support and after went through 20 mins, he guided me to erase all content & setting features. In recovery mode, I could not erase the disk or any volume cause it all failed. So he made appointment for me at Genius Bar the next day and they exchanged a new one for me but the same problem happened + the Activation Lock status is disabled even my iCloud logged in + Find My Mac toggled on

I called Apple support, nothing solved after passed 3 advisors in 4 hours then they set appointment with a Senior Advisor in next early morning. Since 8am till 12am, the result was another appointment with Genius Bar again then assured with me all the things was described in my Case ID. So now is the interest part

I came back, showed them but this time the ask my why do I had to get into the flashing file because that is the hidden file in private-var-db. I asked why not. I bought it and it's mine. He told me that he's worked 12 years and the Mac is normal. After exchanged another new one, I stayed there to unbox and set up with new Apple ID but same problem happened. They were mean with me and the guy (I think he's in charged) told me the Activation lock status: disabled mean it good and they have a class for those basic knowledge if I want to take. I told him why all Apple support Advisors + things I read in Apple website is not that mean. He told me that they are the one in store not the Apple support Advisors. I had to bring it home due to the store had no more M4 with same upgrade features.

I don't know who was wrong and who was right. Please tell me what should I do because my town just has only 1 Apple Store and I'm gonna out of the State on next month. Sorry for my limited English, hopefully you don't mind.

[Re-Titled By Moderator]