Rendering issue with reaper (bounce in place)

[beatelite1]

Hi.
When i try to render a few 4 bars long midi clips from VSTi Instruments and it will only catch up the last Bar. When i leave at least 16 bars pre-gap it in the time selection will catch the full 4 bars.
First Photo is only the Midi Clip selected , Second Photo with 16 Bars pre-gap.