Dungeons not spawning in minecraft 1.15/1.15.1

Minecraft dungeons (The cobblestone box with spawner inside) does not seem to generate at all in my world. I have tried using dungeon locators and found that the given location has no dungeon. I tried flying around in spectator mode with night vision for quite some time and I still cannot locate any dungeons.

Seed: -5381259858581377300
(The world was geneated in 1.15 and I updated to 1.15.1 later on, but chunks had already been generated)