Sonar Artist no playback and zero output level after cutting audio track

Hello,
I recently bought a new laptop (Dell XPS 9560 with an SSD disk - no shortage of CPU or RAM or disk space).
Sonar always worked very well on my previous laptop but since installing on the new PC (Windows 10, clean install downloaded from cakewalk) I have a problem with playback.
If I import an audio file into an audio track and play it back it is OK (just one track, no effects, just playback from an imported .wav file).
If I then cut a part of the audio track then try to play it back there is no sound. The clock is advancing but the level meter for the track is showing zero output.  It doesn't matter how long I wait, hitting "play" results in silence and an advancing clock.  There's no MUTE and the track volume has not been altered.
I then found that if I re-select the sound card for the track output (realtek, which is already selected) then Sonar starts processing something for 10-15 seconds (on a high-end PC with a track of 5 minutes, 16 bit at 44.1kHz), then it starts to playback.
The settings are all the default settings although I did try various buffer/latency settings but this didn't help and I put back the defaults.
I thought there may be another application running and interfering so I removed Groove Music, but that hasn't helped either.
Could you help me resolve this problem. SONAR is not very useful in this state.
Regards,
stowyn.
 

Hi again,
 
I tried with BandLab and did not see a problem with playback (after cutting and moving as before).
 
In Cakewalk, I've tried loading different files (mp3, wav) and I get the same result.
The procedure is simple: I create an empty project, add an audio track, and drag a music file into it.
I then select the first few minutes, cut it out, and drag the remainder back to the start of the track.
On PLAY, no sound comes out.  If I then re-select the already selected Realtek output then Cakewalk is busy for 10-15 seconds then starts to play.
 
Note: I also tried installing the latest Realtek drivers. (Audio Codec: Realtek ALC3266). I tried the latest drivers from Realtek, then the latest drivers from the Windows 10 device manager update - still to no avail.
 
Shouldn't the track output indicator indicate what's being output by the audio track.  I would have thought this would show a value regardless of whether it gets to the sound card or not?
 
Regards,
Stowyn.

When I put the mode to MME then I don't get the problem. However the quality is not as good.
I read on the forum:
<<<<<<<<<
ASIO is usually the best (get the newest ASIO drivers made for your audio interface)
WDM can work equally well.
ASIO4ALL is not ASIO, but a WDM-wrapper.
MME 32 is the poorest one, often required for USB mics and integrated soundchips.
<<<<<<<<<
The fact that it works in MME mode seems to indicate that there is a problem with the ASIO interface and that is quite annoying since I would have expected the audio interfaces to work correctly on a decent PC.  My old PC had no where near the performance but behaved perfectly using ASIO.

Strangely, I just re-installed the latest driver from Realtek (I was using the Windows 10 driver update version when I tried the MME mode) and now the ASIO interface appears to be working normally! It's as though passing through MME mode has reset something.