Nintendo Switch Online crashing worlds

I've done a bit of testing with this bug, and TL;DR, having Nintendo Switch Online seems to crash the game when attempting to enter a world.

 This starts on January 7th. Me and my friend played Minecraft together with no problem.

Now, the next day, January 8th, we tried to play together on the same world. It did not work, the game crashed upon entering the world. I tried to make a new world. It did not work.

I decided to do some testing on my own. So, I opened Minecraft with our guest user, that does not have a Nintendo account linked. Opening a world worked, interestingly. Next, I launched Minecraft with a user that has a Nintendo account linked, but no Switch Online. Entering a world worked.

Today, on January 9th, I tried to open the same world on the user with Switch Online. It failed again.

Because I do not have any data with my friend's console, this may be a problem on my end. But considering it only happens with Switch Online, it also may be a problem with Minecraft or Switch Online itself. This is all of the data I have so far, I will test a bit more tonight.

Steps to reproduce:

1. Have Switch Online

2. Open Minecraft (Bedrock Edition)

3. Enter / generate a Minecraft world

4. Wait for the world to load

5. Crash!