Stolen iPhone lost from Find My List

Hi all!

My iPhone 13 was stolen a week ago. First of all, of course, I turned on the lost mode and contacted the police, the phone was already switched off at that time, so the lost mode was displayed with the status "Waiting". The only problem was that Find My was turned on, but the "Find My network" and "Last Location" were disabled, so I couldn't see the phone's location in offline status.

I couldn't sign in to my Apple ID because of two-factor authentication, and my phone was stolen along with my SIM card. Today I received a SIM card with the old number, signed in to my Apple ID from another device. An hour after logging in, I received an official message that the phone was found:

Your lost "iPhone 13 Midnight" has been discovered.

View location: *link*

Apple Support

However, after logging in, a strange thing happened — only my new iPhone was now shown, and the lost one and the Apple Watch disappeared from the list!

These devices are still in the Devices tab in iCloud, but they no longer appear in Find My.

What happened and what to do next?

UPD: I should add that after receiving the Find My message on the lost phone, it completely disconnected