I am reporting only the issue with the world not visible to me but visible to LAN players (hence those being the screenshots). The mention of the crash/rollback was an aside in case there is a relationship to this. Surely you need to know that there is more than one glitch in order to locate the issue (one issue in the code can cause multiple issues further down the line)? Apologies if my report isn't clear. I'll just re report the same issue without mentioning that other errors are happening as well.
Happening today on my daughter's Kindle when she enters a LAN world. Only happening on this one world.