Aja output not functioning in new plugin

Hi.
When I set output SDI by AJA Kona4 with Fill only.
My setting with the kona card in UE4.20:

  • Port 1: for input live with 1080i50
  • Port 4: for output with 1080p25

I get this message when play the level:

“LogAjaMedia: Warning: Lost 6 frames on Aja input [aja://device0/port1]. UE4 frame rate is too slow and the capture card was not able to send the frame(s) to UE4.”

How can I fix this?

Thank you so much