Apple loop does not preview while playing a track

Since the last update of Logic pro X, I am not able to preview apple loops while I am playing the tracks. When the track is stopped, the apple loop sounds, but when the tracks are playing, it shows as if it was playing but there is no sound. I checked the "Preview channel" and everything looks fine."

In the first screenshot, the track is stopped and you can see the Apple sound metering in the Preview Channel. In the second picture you can see that while the track is playing, the speaker green icon is "on" (as it was sounding), but there is no signal in the Preview channel. Help please! Thanks.