.5 sec Delay of current project playback after new audio or midi track to existing project

When i record or add an audio track, or midi track from external keyboard to an existing project, the existing project seems to be delayed by half a second during playback..  my projects consist of old midi loops record on my old ensoniq keyboard workstation. I load the midi tracks into Sonar via floppy disk and, then use Sonar to trigger the sound on the keyboard and record the audio output of keyboard back into Sonar. newly recorded tracks not synced with current project tracks.. it was working fine before.. started few days ago before last night update.  my projects are usually about 20-25 tracks of audio.  I remove and re-install Sonar, re-install ins def file, still the same.. maybe a settings issue but i can't figure it out.. help!!!!
 
Using
windows 10, Intel I5 - 6200 processor, 16GB Ram
Sonar Professional
Presonus USB Audio box
Ensoniq MR61 keyboard for sounds