USB keyboard hangs after pressing CapsLock / NumLock key

I’ve got QNX 6.3.2 on SBS computer with USB keyboard (“tracer”).
/it is without PS/2 controller;

That keyboard doesn’t work for a 15-30 seconds (or forever)
after pressing “led keys” (Caps Lock or Num Lock or Scroll Lock).

Do You know how to solve this issue ?

Have you checked with the driver available for USB? I have used USB keyboard & mouse with restriction in number of USB ports I can use. My PC with QNX 6.2.1 was supporting only one port at any time. But the issue you have mentioned was not creating problem.
based on my issue I called QNX and came to know from them, that they were in process of fixing the bugs in USB driver for their later version. as you are working in 6.3.2 there should not be any such issue.
Why don’t you check with QNX tech support??