PS/2 to USB converting for IBM Model M not working properly

I have an IBM Model M keyboard with terminal connector (similar to RJ45 socket) with model number 1394108 (as image below): I connected the wires to a PS/2 to USB converter like this images It works but not correctly: when a key pressed one time (for example z key), it type that key code infinitely (zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz). In the Other word, keydown works but keyup don't work. Is this problem from the converter or is related to keyboard? How can I fix it?

Question by Khabarkhaan on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.