Jumanji Theory!
Okay, quick disclaimer! For me to explain this theory i need to have some spoilers otherwise it will be very arduous to understand. So please go watch both Jumanji movies before reading this. If you would like you can go read my review on Jumanji; Welcome to the Jungle.
Let's start with where it all began with the Robin Williams classic. At the end of the classic movie the children who were once victims of the broad game's antics forget about what happen entirely including who Allen Parish even is. While the adults still remember. Now, the adults knowing the powers of this so call "fun" game would never pick up the game on a beach. This is where the new movie picks up. A father finds the game while having a run on the beach. Now my theory is that Allen Parish and Sarah would have been very old at this point considering they were in their late teens in the 1950's but the children would be just old enough to have their own kids. That means there is a slight chance that the father who picks up the game for his son is the boy from the classic. He wouldn't know any better considering he forgot about the game and don't you think it is weird that the game that clearly has a mind of it's own lands on the beach that he runs on. Also, considering that the game seemed pretty angry it had to go back. It would want to come back for revenge. I also think this would make the movie even better because it would be another nod to the classic.