tygb wrote:
The Mac you have purchased seems to be refurbished , the seller didn't followed the steps …
That is not the cause of these iCloud verification prompts. I have these messages too, and these devices are all direct purchases from Apple and with no previous owners.
These verification prompts are seemingly a routine part of recent iOS and iPadOS versions, as well as on recent macOS.
macOS particularly can trigger this when iCloud Keychain is in use:
If your Mac keeps asking for your keychain password - Apple Support
I meet this prompt on something every day or so; on some logged-in device.
There are cases where these can be triggered more often.
And a general suggestion when things go weird: if there’s an add-on VPN around, or add-on anti-malware around, remove it per the vendors’ instructions, restart, and test again.