no such thing as a mandela effect; it's just a tavistock psyop.

Funding was provided by the British royal family, and later by the Rothschilds to whom Lord Northcliffe was related through marriage. Arnold Toynbee was selected as Director of Future Studies. Two Americans, Walter Lippmann and Edward Bernays were appointed to handle the manipulation of American public opinion in preparation for the entry of the United States into WWI, and to brief and direct President Woodrow Wilson.

http://www.thirdworldtraveler.com/New_World_Order/Tavistock_HumanRelations.html

more:

https://newsspellcom.org/2017/06/30/__trashed-2/

https://www.reddit.com/r/MandelaEffect/comments/7c5322/dont_call_it_a_psyoplets_call_it_memetic/