Steps to reproduce:
Run a realm with custom resource and behavior packs on the active world (Demo pack attached)
Invite members
Press the back button

Observed results:
Realm says "Applying Packs" and restarts the realm

Expected results:
Realm invites members with no impact on gameplay.

Other information:
After inviting members, can force close the app. They will still be invited, but it will not try to apply packs and restart the realm. 
This may apply to other realms screens, but is most noticeably impactful when simply making changes to the members.