I've noticed that when my world autosaves, it kicks out my friend who is playing cross-platform on PC and there's nothing that can be done about it. At first, it would only kick him if he would interact with something (such as a door) or mine a block during autosave. However the bug has progressed and he is kicked out regardless of what he does, even if he stays completely still during autosave. If this bug cannot be solved, I hope there is either a feature to reduce the frequency of autosave or turn it off altogether and this issue has been going on for quite some time. 

Sometimes my friend cannot even join back as my world no longer appears in my friend's multiplayer tab. The only way we can fix this is to completely restart the Switch and open Minecraft again. The internet is certainly not the issue as everything else works perfectly on the Switch and my console is very close to the router.

The screenshot attached is from my friend's PC.