Warning conflict when editing a page [Since XWiki 11.5RC1]

NOTE: Realtime WYSIWYG should not be activated. To deactivate it, go to Administer Wiki > Editing > WYSIWYG Editor > Disabled Plugins drop-down and add (tick) "xwiki-realtime" in the list then Save.

1. Login as Admin and create an user (e.g. U1)
2. Edit a page (insert e.g. 'edit1')
3. Click 'Save'
4. Open a different browser (or an incognito window) and login with the user (U1)
5. Go to the same page and (force) edit it
6. Add some text e.g. 'edit2' on the same line
7. Click 'Save'
8. Go to the browser where Admin is logged in and type a word (e.g. 'edit3')
9. Click 'Save'
10. Select 'Merge and fix conflicts with your changes' and click 'Save'
11. Repeat steps 2-9
12. Select 'Force save your changes' and click 'Save'
13. Repeat steps 2-9
14. Select 'Reload the editor' and click 'Save'
15. Repeat steps 2-9
16. Select 'Fix each conflict individually'
17. On the bottom, select each option: 'your current changes', 'before your changes', 'latest version saved', 'custom version'
18. Pick an option and click 'Save'