I hope you check back in on this... In the meantime it is normal for some apps to receive a code via text and extract that code from the message and just allow you into the account/app. So really that isn't all that sus. As for your accounts not allowing you to change your password for them you would have to tell us what accounts and types of accounts these are. For some it may matter where these attempts are made, through the app, online in a browser or some other way? Please do not include any personal data in your reply just which ones you're talking about, like Facebook, Gmail, WhatsApp... etc.
We'll also need other information and screenshots to really be able to address your concerns.
How long has this been happening or when did you first notice this?
When you say, biometrics have been removed, are you saying that without using a fingerprint or face recognition your phone can be opened anytime just by swiping it open, or are you now forced to use a pin/password/pattern?
Are you using a service like Google Voice, Google Voice is not the assistant that you talk to or ask questions of it is a service that includes voicemail but that also gives you a secondary phone number, or anything like that where you have to use call forwarding to use the service?
Have you ever used call forwarding on this device? Each carrier uses different code or method for setting up call forwarding, have you tried using your carrier's End Call Forwarding code to see if it affects this forwarding message you get when receiving a call? If you want help finding this code you will have to tell us who your carrier is.
When you say that you're being logged out of accounts, do you mean that your email app stops receiving messages and when you open the app you have to log in or are being prompted to log in before it updates or something else? If you mean the app, what app are you using? There are several reasons that email apps "log out" and it is usually related to the app more than the account. If you're able to just log right back in with the same credentials it almost sounds like situations that can occur with some apps where they won't allow access through two devices at the same time. This rare with email but could be app specific.
Join and drop us a few more hints if you're serious about wanting help.
Best wishes.