Nether portal linking appears to be broken

Steps to reproduce*
1. Open this world Pale Farten.zip
2. Go through the portal in front of you
3. Once you arrive in the nether go back through the portal you came from
4. You will spawn in a cave
5. Break the portal and tp back to the first portal /execute in minecraft:overworld run tp @s -34 65.00 -109
6. Repeat steps 2 & 3

Observed Results

• After doing steps 3 & 6 you will create a new portal in a cave instead of going back to the portal you first used.

Expected Results

• You would return to the portal you first entered instead of making a new one