All natural hostile mobs stopped spawning

All natural hostile spawns have stopped on my realm. example if i find a new sea temple i see guardians. do a peaceful reset and go back to hard mode. nothing spawns back. if mobs are killed off they wont return. on hard mode in the middle of the desert i could go afk without fear. so far my slime farm, broke, guardian farm, broke, squid farm, broke. Spawn cages still spawn but are slower then normal. I now know of two realms its happened on. they both arhave cheats activated and both have players playing survival hard. in my map all these broken farms worked after the most recent update. it was only a day and a half ago now this started. please understand its not just bad spawning conditions.. middle of the night on hard in an unlighted desert, forest, jungle, anywhere I should be getting attacked and i am not. the game still registers as being in hard mode because spawn cages and spawn eggs work. Please help. Will gladdly have you on the realm to see whats not going on..