This is not trivial as it requires forcing a _JAVA_Choice override at launch (or system large).

Diagnose

To diagnose this as the cause, first launch Minecraft from terminal with the _JAVA_Options overridden.

1. Close Minecraft
2. Open 🔎 Spotlight (🔎 in upper proper of Desktop)
3. Search for "Terminal", open the app
Paste the next command in:

_JAVA_Options=-Djava.web.preferIPv4Stack=true /Functions/Minecraft.app/Contents/MacOS/launcher

Attempt to connect with LAN server and see if it fixes the issue

Completely Fix

Using Minecraft Launch Options: @TheOnlyMrCat supplies a technique here that does not contain enhancing any recordsdata by hand. Please try that earlier than making modifications to the Minecraft launcher.

Patching the launcher manually:

Use this method solely when you've got issues utilizing @TheOnlyMrCat's solution.

This _JAVA_Choices override could be provided in many places however since launching from Terminal shouldn't be ideal, we need to use a technique that fixes when clicking on the icon. At time of posting, the Apple beneficial method for offering overrides is contained in the App bundle itself using one thing called LSEnvironment

1. Optionally set up a Text Editor akin to Atom to edit XML files.
2. Utilizing Finder, go to Purposes
3. Locate (don't open) the Minecraft App
4. Proper click on Minecraft, Present Package deal Contents
5. Go into the Contents folder and find Data.plist
6. Right click Data.plist, Open With, Atom (or TextEditor)
Close to the bottom of the file, add the following in between the LSEnvironment _JAVA_Choices -Djava.web.preferIPv4Stack=true

Sadly this doesn't take effect straight away. MINECRAFT SERVERS is because of the way Mac caches it's launch providers.