I was playing on my single player survival world, and I went into the nether and set it to easy so mobs could spawn, I found a fortress and blazes weren't spawning I tried relogging, setting it to different difficulties, I made a backup and tried there but the blazes were still spawning, there were also a lot of ghasts im not sure if it was an abnormal amount but there were a lot and a few other mobs I couldn't find either, I tried making a completely new world with the same seed and still blazes couldn't spawn here's the seed:-2080465551705610451