Online search doesn't find all files

Hello,
I noticed that the online seach bar doesn’t find all files, even though they have the same format (mp4 for example) and are in the same folder like other files that can be found every time by typing the file name in the search bar.
I don’t understand why certain files just can’t be found. Either the search result shows nothing or the result shows a bunch of other unrelated files.
Even after renaming the file it still couldn’t be found, so the problem must hide somewhere else in that file, not just in the file’s name. But it’s just a simple mp4 file which is playing fine with all apps, also on Icedrive.

After mounting on desktop however I can find every single file when searching by windows explorer, but this way of searching is much slower than online. Furthermore, the upload function is not 100% reliable on the desktop app, as others already mentioned. That’s why I prefer to use Icedrive online. If it only could find all files.

Just out of interest, can you give us the name of the file(s) it doesn’t find?
Are there maybe special characters in the name?

Well, at first I have to apologize that I was partially too stupid to search properly. The mentioned file was named “Golden Bat” and I found it today among a huge bunch of unrelated files, I think I was just too blind yesterday (I was tired from work and poorly concentrated). I also remember that I was unable to find some ISO files and other folders in the past, now months after trying to search the same files again, it suddenly worked. So either the search has improved or I was really too clumsy at that time.

But my topic was not entirely in vain as the search has some issues nevertheless:

Both files are in the same folder:
Filename: 臥虎藏龍 = Found!
Filename: 金較剪完結篇 = No search results!

Both files are in the same folder:
Wrath of the Sword = Found!
Warrior’s Tragedy = No results!

File name “Tag der Rache”:
Found among over hundred (!) of unrelated files that all contain the letter combination “der”, “WanDERing Dragon”, for example.
If you search with the term “der” only and you find so much files, then everything is fine.
But if you add more words, then it is inconvenient to show a huge bunch of files that do contain only one of the searched terms.
Well, if you know you should leave out frequently used terms and letter combinations, you can find a file quicker, but it is inconvenient always to check all terms on often used letter combinations before typing something into the search bar. I wish there would be an option to show only the searched combination of words, just like it works with Google when using quotation marks.

I also wish that all search results (single files, not folders) would provide an option to go directly to the file’s location or at least show the file’s path somewhere in its preview or properties.

Update:
“Warrior’s Tragedy” couldn’t be found because I just wrote “Warrior’s” without “tragedy” as I assumed it can be found just like other files that can be found by using only one of its name components. It is the apostrophe that is causing trouble here. If writing both words, the apostrophe is ignored and the file can be found thanks to the word “tragedy”.

As for the Chinese file name: I found out the character “結” (tradtional form) is causing trouble here, searching with the other characters works fine. I’m sure there are more characters with the same issue.