Steps to reproduce bug:
1: Launch game and sign in
2: Press Play
3: Create New World
4: Press Create on Realms
5: Press Add new 10 player Realm
6: Select Buy Now
7: Rename (in my case "Blockstead")
8: Check the I agree box for terms of service etc
9: Press Buy Now

Result:
A window briefly pops up (too quick for me to analyze) and is replaced buy a window stating:

Store Connection Lost 

Your device lost connection to the store and we can't confirm this offer is still available. Please check your internet connection or try again later.

Expected result:
Some sort of billing screen

Reasoning:
I know my internet connection is not to blame as i am able to buy minecoins (i tried just to test) and I am able to view the store, my other games are unaffected and I can join my friends realm fine and I can even host a bedrock server, i desire to run a realm instead though for the ease of access across different systems.