**Steps to replicate the issue** (include links if applicable):
* Enter `Гдов` in your search box at https://ru.wikipedia.org/ | API request: https://ru.wikipedia.org/w/api.php?action=opensearch&format=json&formatversion=2&search=Гдов&namespace=&limit=10
* Go to https://ru.wikipedia.org/wiki/Special:Search and after choosing some namespaces set ‘Remember my current selection’
* Enter `Гдов` in your search box again | API request example with main namespace: https://ru.wikipedia.org/w/api.php?action=opensearch&format=json&formatversion=2&search=Гдов&namespace=0&limit=10
* Compare the results: without namespace selection, results start with `Гдов`, with it, results are pretty random
This is also happening in Vector 2022 without that setting involved, just in https://ru.wikipedia.org/w/rest.php/v1/search/title?q=гдов&limit=10 API requests. Previously this was not the case.
Report on Russian Wikipedia tech forum: https://ru.wikipedia.org/wiki/Википедия:Форум/Технический#Проблемы_с_подсказками_при_поиске
{F36975486} {F36975489}
**What should have happened instead?**:
Results should have titles that start with entered input no matter the current user settings.