Mobs have stopped spawning after continuously switching from peaceful mode to hard mode

I play on minecraft bedrock on the ps5, i would switch from peaceful to hardcore continuously when setting up my villager farm. Now all of a sudden they just stopped loading on to my world. They will only briefly spawn when im near a zombie spawner but upon coming back to my base they're arent any. Ive checked other worlds and mobs spawn in just fine. Please Help! I dont want all my work to be for nothing if i cant even find one singular zombie