Dump1090 and fr24feed running both

Hello,

I have a problem with my Pi. I installed dump1090 and fr24feed. It works fine but only when there is only one process running dump1090 or fr24feed. When both processes are running at the same time then I'm not feeding to flightradar. When only fr24feed is running then I'm feeding data to flightradar.
Does anybody have idea what's going wrong?

Dan