To reproduce:
- Go to the search page.
- Change search language to Chinese, search for ζ.
- Result tells that there are 826 matches.
- Click Next or a page number at the bottom.
- Search language switches back to English and Pali, and there is no search result.
This is due to the wrong parameter in those page links and Next link, they use query_lang instead of lang, so it reverts back to the default, which is English and Pali. As a workaround, one needs to change the url manually, or just change the limit to return every result in one page.
This happens to other languages too.
And I think Chinese in Search in should be changed to Literary Chinese or Classical Chinese.