New sign-in alert

About an hour ago, I received an email saying that there had been a sign in to my 1Password account from a new device (Safari extension). From the message, I couldn't tell on what hardware this took place, so I followed the guidance, logged in to my account, and reviewed the devices linked to it.

Although the recent ones looked familiar (the device names, IP addresses, and locations were correct), the OS information was wrong. For example, the iPhone showed iOS 17.4, whereas I'm running 26.1. The version of macOS was also incorrect.

To be safe, I unlinked all the recent devices and reset my account by generating a new Secret Key and password. I was able to log in on my two main devices using this information plus MFA (see below).

I'm in the Manage account page on my Mac and can see it as Your current device, but the macOS version is still wrong.

I have three related questions:

1. The incorrect versions of macOS and iOS threw me and perhaps led me to reset my account unnecessarily. If this information isn't reliable, why is it shown?
2. As above, I wasn't able to tell what hardware had been used to sign in to my account in the first email notice. What is the best way to do this?
3. I have MFA set up using the Authenticator app on my iPhone, and it was active at the time I got the notice. If so, does this mean that an unauthorized user couldn't have signed in to my account, and am I good to go?

Thanks!