Connection question

[dsealer]

I'm hoping to get some feedback that will help me understand what's happening with my midi connection. I must tell you all I know very little about the midi world. I sometimes am capable of getting one instrument into one channel and record it. How to communicate using midi lingo is even worse.
So today it seems I would loose my keyboard connection to Reaper. When I first boot Reaper everything works as I expect it to. After a few minutes The keyboard no longer triggered the midi instrument. The keyboard was still sending keyboard sounds but not my midi instrument. However if I played the instrument via the virtual keyboard the instrument did emit sound. When I would reboot Reaper everything would work again as before but then after a few minutes it would stop sending the midi signal again.
I'm sure my explanation of what happened is thoroughly inadequate and confusing to say the least. I am hoping someone may understand and be able to give me some trouble shooting ideas.
I'm using a kurzweil 2500 into behringer xr18 to reaper.
Thanks,