The Bug
The "n" in "Realms news" isn't capitalized despite it being a main word.
The "r" in "Leave realm" isn't capitalized despite it being a main word.
The "r" in "Configure realm" isn't capitalized despite it being a main word.
The "o" in "World options" isn't capitalized despite it being a main word.
The "b" in "World backups" isn't capitalized despite it being a main word.
The "w" in "Reset world" isn't capitalized despite it being a main word.
The "s" in "Your subscription" isn't capitalized despite it being a main word.
The "d" in "Start date" isn't capitalized despite it being a main word.
The "s" in "Extend subscription" isn't capitalized despite it being a main word.
The "r" in "Delete realms" isn't capitalized despite it being a main word.
The "r" in "Expired realm" isn't capitalized despite it being a main word.
The "r" in "Open realm" isn't capitalized despite it being a main word.
The "s" in "Invalid session" isn't capitalized despite being a main word.
The "o" in "Client outdated" isn't capitalized despite being a main word.
The "p" in "Invite player" isn't capitalized despite being a main word.
The "r" in "Open realm isn't capitalized despite being a main word.
The "s" in "Extend subscription" isn't capitalized despite being a main word.

This document MC-189261 - Realms Strings.xlsx lists all affected realms strings.