interrupt sharing

Hello, there, I am struggling to use interrupt sharing with my motion control card, which has three hardware interrupt sources, all of them use IRQ5 to request interrupt,

I had no problem with individual interrupt source, which worked well, but if I try to enable more interrupts, it stops working,

what particular notice should I know about sharing interrupts in QNX?

thank you!

when I enable more than one sources, it seems the program never goes into the ISR handler, like no interupt triggered at all.