My server's difficulty is on normal, the monster spawning setting is turned on, I did the /gamerule doMobSpawning true command, I currently don't have any plugins and still nothing. I noticed the spawners weren't working, so I went in creative and just tried spawning a blaze with a spawn egg, and it appears for a brief second, makes a noise, and disappears. I then tested it with a pig spawn egg and it worked fine. So it's just hostile mobs that are the issue. Can someone please help me?