Players cannot change slots when the game is started offline due to Marketplace loading screen loading forever, until it is then connected to the internet again.

Steps to reproduce:

1. Make sure you have an internet connection before opening Minecraft (Preview) (as a control)
2. With Minecraft (Preview) Open, go to the Dressing Room
3. Wait for the Marketplace screen to finish loading if you entered early enough
4. Observe that the profiles can be swapped
5. Close and exit Minecraft (Preview) (end of control)
6. Turn off / disconnect any means that connects to the internet (Wi-Fi, cellular, and even Ethernet)
7. Reopen Minecraft (Preview)
8. Go to the Dressing Room again and wait for Marketplace loading screen

Expected result: You could then just change slots / profiles regardless whether you're online or not
Observed result: The Marketplace loading screen from the Dressing Room takes forever to load, until there is an internet connection again

Note May relate to MCPE-181194, and only affects Minecraft Preview for now