Wandering trader no longer spawns in my world

In my Minecraft bedrock edition world, all other mobs are spawning normally, but I haven’t seen a wandering trader for a very long time. After switching to Creative mode and checking, I confirmed that minecraft:wandering_trader_event is set to true. After discussing with a friend, we suspected the issue might be caused by a trader llama that was tamed and equipped with a chest. In his world, the problem was resolved after he found and killed that llama. However, I haven't been able to locate the llama in my world, so the wandering trader still hasn’t appeared.