TYPO3 Core

Steps performed:
1. created new page with Japanese title
2. added Japanese sample content to that page
3. searched via BE search (icon in the top right corner) for the same Japanese string
4. no results given in the list module, no records coming up

See screenshot.

Remarks:
a) the search term gets "%u65e5%u672c%u8a9e" in search string of the result page (list module)
b) searching the same term by using the field "Search String" in the list module will show the results correctly

this BE search error will also happen when using other double-byte languages e.g. Chinese, Korean
(issue imported from #M15167)