Select the Delete All option to free up iCloud Storage. Method 2: Turn on Optimize iPhone Storage. The second solution to your problem of "iCloud storage not updating after deleting photos/messages" is iPhone Storage optimization. You can turn on the Optimize iPhone Storage feature to get rid of this issue. Here's how to do it:
Click "Messages" under "Messages & Contacts" option, turn on or off deleted items display (optional) to view the deleted iMessages, and hit "Recover" button to recover deleted iMessages from iCloud backup files. Easy, right? What you need is an iClount account and password.
You need to go to settings - iCloud and toggle off Messages. If you delete that thread it will be local to your device but that thread will still remain in Messages in iCloud since you haven't deleted it from there. Just remember if you turn it back on on that very same device the thread will show up again. 06-20-2018 07:21 PM
For all discussions about Apple, iPhone, iPad, Apple Watch, or any other off-topic discussions, please move the discussion to the relevant subreddits. You can update to 11.4 beta and disable Messages in iCloud. But I don't know about downgrading afterwards. Although you'd probably be alright.