Go to other device to approve THIS iphone (2 Factor Verification)

Hi Team,

I have an iphone 8 plus and mac book pro. I am not able to login to both the devices using my iCloud credentials.

After doing most or all of what was required for the two factor authentication, I discovered that: in settings, under my name, it says "Update Apple ID Settings" When I click on that, it says, "Some account services require you to sign in again." When I select "Continue," it then asks for my password. When I enter the password and hit OK, it asks me to enter my passcode.

When I do, I keep getting this message: "Approve this iPhone. Go to one of your other devices signed in to iCloud to approve this iPhone." Below that, I continually says, "Waiting for approval."

Also noticed that I have an option when it is "Waiting for approval" mode (on the iPhone) that says: "Can't approve this iPhone?" That leads "Reset Protected Data" or "Cancel"

How to get out of this endless loop

Any help would be appreciated.Thanks in advance.