Basically, whenever the Host of a non-realm world playing on Nintendo Switch begins typing something to send in chat, all other players receive a major lag spike causing death in-game from jumping off a single block of scaffolding (for some reason), Block respawns and respawns (which have also caused death, in-game), GUI not opening, mobs getting the advantage as you aren't actually moving for them making you an easy hit, and a lot more problems that would probably take a while to list.

Steps to reproduce
1. Join a Nintendo Switch Player's world
2. Wait for them to type in chat

What will happen?
Chances are that other players within this world will experience severe lag, the host's client will remain unaffected.

What should be happening instead?
No lag at all, or at least minor lag that won't cause any major gameplay issues for other players on that world, Realms are unaffected by this as there is no set host.