Strange character matches in media explorer search

[Paul Eye]

I stumbled upon some strange behaviour in the media explorer search today. I was simply looking for the term "DJ" in my music database (which includes my entire music collection) and to my surprise I got matches that initially didn't make any sense to me. Some files (or a part of their name) that matches "DJ" in that search (not including files that actually have "DJ" in the name):

Babymetal feat. Joakim Brodén (artist)
Medúlla (Björk album)
Mydä (artist)
Le Départ (track title)
On The Champs-Désolés (track title)
Götterdämmerung (part of a track title)

and so on. After a bit of head scratching, I figured out what this is (but of course not why this happens). All of the artists/titles above have some letter with an umlaut/accent/diacritic after the letter D, so for some reason these are matched in the search results. This works with any other letter+umlaut/accent/diacritic combination, but that umlaut/accent/diacritic match starts from the 2nd letter you type in (and any subsequent letters). For example, typing in "yx" in the search matches all my files with "Aavepyörä" in them, since for some reason "yx" matches "yö". To clarify, if I type in "xh" it doesn't match "Öhr" (in the artist name "Fredrik Öhr") since this matching doesn't start from the first letter.
Also, not all letters from the 2nd one onwards match any letter with an umlaut/accent/diacritic, and the logic behind this seems to me completely random. I've been trying different letter combinations here, and it just makes no sense to me.
Worth noting is that vowels don't seem to be matched, so for example "da" and "di" don't match "Brodén" from the above list ("de" does of course, as expected), but "db" does, as does any other d+consonant combo, except for some reason "dc" and "dn" don't (in this case). Another example is that "ldt" matches "Tim Schuldt" (of course) but also "Frankie Látó", but not the track title "Negribas iet gulēt", which again is matched to "lbt", "lft", "lmt", "lpt", "lqt", "lvt" and "lxt" but not the other "l+consonant+t" combos. Of course it's impossible to go through all (practically infinite) combinations to find out what matches what, but I hope this is enough to give you a hint of what's going on here.

I didn't post this in bug reports since this is more like an annoyance, especially since I have quite a lot of music with umlauts/accents/diacritics, but not much of that music collection ends up in anything I do in REAPER (for I guess what is obvious reasons).

Windows 10, REAPER 6.79 (both 64-bit). Windows display language is set to "English (Finland)" which afaik is based on English (UK) with a Finnish keyboard layout. If that makes any difference.