Hi Itamar,
Are you setting a breakpoint within your MyFunc interrupt handler? Are there any other breakpoints set? Can you describe the steps you follow to reproduce this behaviour - for example, do you load the DXE and run to main, set the breakpoint in your IRQ, set the target running and expect it to hit the breakpoint in the IRQ?
If screenshots would help illustrate the behaviour, use the "Use advanced editor" option in the top-right of the reply box, and embed/attach images to your post.
Thanks,
Craig.