Thank you for your clarification and examples.
I installed indic fonts on my computer, so things are visible now
I looked at the first 3 characters in your example:
క కా కి
and converted them to their UTF8 code:
e0b095 e0b095e0b0be e0b095e0b0bf
As you can see, they all start with the same byte (e0b095), but they are of course not the same.
I also looked at the disappearing link you mentioned by creating a test course in Telugu, with glossary and 3 Items: క కా కి . 3 variants, which should all sort under క, but the whole alphabet is one link. Obviously something goes wrong here and should be fixed. This might be the root cause of the problem, rather then the sorting - I don't know.
I filed a bug on https://tracker.moodle.org/browse/MDL-65989 where you can add further comments and vote for it to be fixed.
I installed indic fonts on my computer, so things are visible now
I looked at the first 3 characters in your example:
క కా కి
and converted them to their UTF8 code:
e0b095 e0b095e0b0be e0b095e0b0bf
As you can see, they all start with the same byte (e0b095), but they are of course not the same.
I also looked at the disappearing link you mentioned by creating a test course in Telugu, with glossary and 3 Items: క కా కి . 3 variants, which should all sort under క, but the whole alphabet is one link. Obviously something goes wrong here and should be fixed. This might be the root cause of the problem, rather then the sorting - I don't know.
I filed a bug on https://tracker.moodle.org/browse/MDL-65989 where you can add further comments and vote for it to be fixed.