Password was reset without notification

Hey,

So this morning I woke up with a notification on my phone saying that i need to "verify" the unit. I could do this on my other units, so I did on my Apple Watch, then I was prompted to change my password, and while I changed my password I got a error message that it failed. Note all of this happened in system settings, not some email or anything.

I found all of this odd, since I was just sleeping, and as a tech/apple nerd I have not one anything to prompt this.

I called Apple Support since this seemed fishy and all Apple services where working as they should. I spoke with him, and the only thing he could see is that I changed my password last light, something I didn't do. I also didn't get an email about this email change which is even weirder. He could not help me anymore, so what can I do? I'm not sure if I trust that my account is safe since my PW was according to them changed without my knowledge or prompting 2FA.