I have tried searching here but got no matching results, so I believe it's a new bug.

When an End Gateway generates on the outer islands (by traveling through one on the main island) and happens to generate through chunk borders, the gateway is generated incompletely - only parts inside the chunk where the gateway block is at generates.

Steps to Reproduce:

1. Use this seed to create a world: -261618638
2. Go to the end and kill the dragon (can be done by /kill @e[type=ender_dragon])
3. A gateway should generate on/near the -Z axis
4. Go through the gateway

Observed Results:

• The gateway on the outer islands is sometimes cut by chunk borders and thus incomplete.
  Note: The exact position that the outer-island gateway generates may vary slightly so it's not cut by chunk borders every time; if this happens, delete the world and re-create one using the same seed, until you see the incomplete gateway. Also the result may be inconsistent: while the gateway gets cut by the chunk border, sometimes it is completely generated but sometimes not; some part beyond chunk boundary (in this case, corner of the chunk) will be missing randomly.

Expected Results:

• The gateway should be generated completely regardless of whether it is cut through by chunk borders.