Likely relating to existing permission handling -- see issue #117.
Reported by ert on discord.

In alpha 1.0.0.1, such behaviour would print the teleportation message.
In alpha 1.0.0.4, that behaviour no longer occurs.

Spigot 1.18.2 on windows 10.

Reproduced on Spigot/CraftBukkit 1.18.2 API 1.18.2-R0.1-SNAPSHOT.
This issue seems to exclusively occur with certain permission handlers.

This issue only reproduces for players other than the gate's owner.
Sign interactions work normally; gate connects properly, activation works.
non-op'd players entering gate are rejected to entry portal with a \n.

Going to investigate further into the exact circumstances.

Reproduces on Paper.
I can now confirm that this is a conflict between Vault and GroupManager.

This only occurs when all three jars (stargate, groupManager, and Vault) are present.
Removing either GroupManager or Vault stops this problem from occurring.

Reproduction Steps:

1. Start a paper instance with paper, vault, stargate, and group manager.
2. As an op'd player, make a gate on the central network.
3. As an op'd player, make a gate on the same network, this time thousands of blocks away.
4. As that op'd player, scroll through, activate, and enter the portal; it will work.
5. As a separate, un-op'd, player, scroll through, activate, and enter the portal; it will fail.
6. No reason for failure printed; all activations work fine -- the player is simply returned to their origin with \n in chat.

This was solved during the refactor related to issue #119