Joshua Tuman

I can confirm this happened in my realm as well to at least 2 people.  It seems to happen when switching from one platform to another and back, such as playing on xbox, logging in on mobile for a while, then switching back to xbox again.

I opened a case for the issue of slimes no longer spawning in slime chunks below level 40 and it was closed referencing this one.  I will say in our experience the mob spawner no longer works, or only a few mobs drop every few hours at best, mobs also spawn in well lit areas in and around bases, but, for the most part the mob spawns in the wild at night seem about normal most of the time.