I don’t know the specific methods, but 3G, 4G and 5G do authenticate bidirectionaly, just 2G doesn’t, partially why Android now has “Disable 2G” toggle.
Also probably why they said they can downgrade you to 2G to intercept communication.

What’s happening here is probably similar to anyone being able to send Wi-Fi deauthentification frame to your device to disconnect you. Unless you’re using WPA3.