What I did:
1. Go to id.wp
2. Search "intitle:Mongolia" in all namespaces (except File and File_talk, since it searches Commons also)
https://id.wikipedia.org/w/index.php?title=Istimewa%3APencarian&profile=advanced&search=intitle%3Amongolia&fulltext=Search&ns0=1&ns1=1&ns2=1&ns3=1&ns4=1&ns5=1&ns8=1&ns9=1&ns10=1&ns11=1&ns12=1&ns13=1&ns14=1&ns15=1&ns100=1&ns101=1&ns828=1&ns829=1&profile=advanced
What I expected:
1. At least the country, [[id:Mongolia]] should be on the top, or at least near the top, but instead, the first 20 result (out of 89) was from Category and Templates namespaces. Mongolia came #47 (after the flag, [[:id:Bendera Mongolia]])
2. Expecting some logical reasoning, or at least some explanation of the result, found none.
What else that I did:
1. I tried on three different countries on three continent, "intitle:ukraina", "intitle:nigeria", and "intitle:brasil" with same result:
https://id.wikipedia.org/w/index.php?title=Istimewa%3APencarian&profile=advanced&search=intitle%3Aukraina&fulltext=Search&ns0=1&ns1=1&ns2=1&ns3=1&ns4=1&ns5=1&ns8=1&ns9=1&ns10=1&ns11=1&ns12=1&ns13=1&ns14=1&ns15=1&ns100=1&ns101=1&ns828=1&ns829=1&profile=advanced
https://id.wikipedia.org/w/index.php?title=Istimewa%3APencarian&profile=advanced&search=intitle%3Anigeria&fulltext=Search&ns0=1&ns1=1&ns2=1&ns3=1&ns4=1&ns5=1&ns8=1&ns9=1&ns10=1&ns11=1&ns12=1&ns13=1&ns14=1&ns15=1&ns100=1&ns101=1&ns828=1&ns829=1&profile=advanced
https://id.wikipedia.org/w/index.php?title=Istimewa%3APencarian&profile=advanced&search=intitle%3Abrasil&fulltext=Search&ns0=1&ns1=1&ns2=1&ns3=1&ns4=1&ns5=1&ns8=1&ns9=1&ns10=1&ns11=1&ns12=1&ns13=1&ns14=1&ns15=1&ns100=1&ns101=1&ns828=1&ns829=1&profile=advanced
2. I tried on "intitle:indonesia", got at least [[:id:Wikipedia bahasa Indonesia]] on number 8. Here's the first 7 result (and the English equivalent):
Kategori:Aktor Indonesia (Indonesian actors)
Kategori:Aktris Indonesia (Indonesian actresses)
Kategori:Sinematografer Indonesia (Indonesian cinematographers)
Templat:Kabinet Indonesia (Indonesian cabinet)
Portal:Indonesia
Kategori:Seni di Indonesia (Arts in Indonesia)
Kategori:Film Indonesia (Indonesian films)
Guess the main article on what number:
45. [[Daftar tokoh Indonesia]] (list of Indonesians)
47. [[Waktu Indonesia Barat]] (one of the Indonesian timezone)
72. [[Distrik (Indonesia)]]
88. [[Pemerintah Indonesia]] (Indonesian government)
102. [[Bunga Nasional Indonesia]] (Indonesian national flower)
105. [[Divisi Dua Liga Indonesia]] (Indonesian second division (footbal))
It's ([[Indonesia]]) not on the first 100!
Some expectation:
1. The shortest title first (for one-word search)
2. The most popular page first (search engine like)
3. Last edited page (denotes some activity on the page), those three criteria makes sense, while the current one does not
4. Anything but Category and Templates on the first 100. It seems that there's some weird coefficient value of those two namespaces. IMO main page should have the highest coeff value.
5. (possibly feature request) it could search my watchlist and display them with some differentiation (bold title, star in front of title, etc.)
If you couldn't replicate the bug, I could give some screenshots. (I don't know, does everyone have customized search result anyway -- some "personalization" -- and if so, based on what?) I checked on a logged out mode in a glance, and seem to be the same.