problems when entering in Thai - who ask / report problem to?

some keystroke sequences work randomly or not at all

for example, the widely used word "naam" for water consists of a M, a tone marker, and the "AM" vowel

ิิbelow are two typings of "river" - litterally "mother-water"

แม่น้ำ แม่นัำ

the first example is correct, whereas the second example is not

sometimes it will type correctly, most of the time not. never correctly in vim for example. sometimes correctly in the text editor. never correctly in browser, such as this