As another reply suggested, change Siri in settings to listen while covered.

Took me a minute to forget it was there.

There’s a bug in iOS that lets you bypass screentime restrictions to reset the appleid password. It’s been posted about in some recent threads here.

Better advice is to use a long alphanumeric passcode instead of a short 6 digit pin, and be very careful nobody watches while you’re entering it.

More recent iPhone models can report their location even while turned off, as long as there is someone else near it with a turned on iPhone. It sounds a bit like this has happened.

As others have said you need to call your provider.

But also, it’s too late now but you can set a sim pin that stops someone from moving the sim to a different phone to use it.

More likely that your battery has degraded over this time period as well?