Joining minecraft beta for caves and cliffs update? But not in the latest version?

Your son is playing on the official release channel for Minecraft. His 1.12 version is currently the latest official version, whereas his friends have joined the Insider Program and are playing a beta test version of Minecraft.

His friends can either un-enroll from the Beta Insider Program, or you son can try to join the Insider Program and update his Minecraft to a beta version.

Be aware however, that beta version still contain untested parts, and the game can crash, malfunction and in turn destroy worlds if an error occurs.

If your son is still willing to test the Beta, he can download the free Insider app from the store, and join the Minecraft Beta.

Then he'll have to download/update his Minecraft to the newer beta version.

According to https://minecraft.gamepedia.com/Bedrock_Edition_beta_1.13.0.1 it seems you opted in to recieve BETA updates to Minecraft.

As Beta versions are test versions and might contain unstable code, public servers do not update to Beta versions.

So if you wish to use public servers, make sure you only use non-Beta versions of Minecraft. If necessary, un-enroll from the Minecraft Insider Beta program, and wait until the next official update, or uninstall and re-download the latest public non-beta
version of Minecraft.

Greetings ToddPeterson8,

Sorry to hear about the problems you are having with Minecraft.

I have a couple of questions to help me figure out an answer for you.

1) Are you part of any of the beta programs for Minecraft? The Preview, Accessibility Preview, or Insider flight? These all have different versions that specifically state don't allow multiplayer with people outside the programs because of content restrictions.

2) What was the warning message you received? Would you be able to post a screen shot of it? Please remove any personal information including gamer tags before posting.

3) With the 1.18 updates, these came with the Cliffs and Cave update. This feature also updated worlds with new parameters. This page is Mojangs FAQ for everything pertaining to that update, including how to update your world to these new features. I would take a look here to see if this might be causing your issue as well.

Looking forward to your responses, hope this helps and happy gaming

Hi,

Did you find a fix to your issue?

I purchased Minecraft for Windows 10 yesterday, updated my drivers to the latest version and joined the beta via the insider app. Minecraft for Windows 10 RTX beta was in the list on my PC.

Do you own Minecraft for Windows 10? If you click
this link, does it say you own this game?

I would also make sure that both you and your friends that are trying to join all have the latest version of Minecraft downloaded. Make sure that any available updates are installed. This could also cause a connection problem, if you don't. Minecraft is
always doing updates to the game, so make sure that all of you are on the latest version.