Nether portals created in the overworld mostly link to already existing portals in the Nether

Whenever I travel through a newly created Nether portal in the Overworld and there is an already existing portal in the Nether, the game prefers to link to that portal rather than generating a new portal. The distances between the former and the latter’s Overworld counterpart are over 500 blocks!
Steps to Reproduce:

1. Create a Nether Portal.

2. Go through the Nether Portal.

3. Back in the Overworld, move 500-800 blocks away.

4. Create another Nether Portal.

5. Go through the Nether Portal.

6. Observe that your location is the same as the first Nether portal.