NOTE: This can be fixed by updating Minecraft on the Android 12 device to 1.18.12. Devices running Minecraft 1.18.12 cannot connect to an Android 12 device running Minecraft 1.18.10, but devices running Minecraft 1.18.10 can connect to an Android 12 device running Minecraft 1.18.12

Following the 1.18.10 update, hosting an online multiplayer game on a device running Android 12 does not function properly anymore. The world broadcasts, but the connection never completes (the game gets stuck on "Connecting to external server" and never connects).

Notes:

• This does not affect Android 11 or earlier, and it is possible to join an online multiplayer game from an Android 12 device running 1.18.10
• I made sure that all devices were updated to 1.18.10 before reporting this issue
• All devices were able to connect to the Android 12 device when they were all running 1.18.2
• When the game gets to "Connecting to external server" you can use the Cancel button to return to the server select screen or multiplayer screen (whichever one you selected the Android 12 device from)
• This has not been tested across Android 11 devices that were upgraded to Android 12 after a successful connection, as I do not have any devices that are still running Android 11 but can be updated to Android 12
• If using an older version or a beta, the game will still give you the "Outdated client/server" error like before.