Ripple trim Q & W during live play trigger a rollback in time

Hello,

i have a problem with the Q & W keys in premiere pro, i hit Q when i want to delete what is on the left of my clip and W to delete what is on the right. So far so good, but i when i do this while my head is playing, right after i hit one of the two keys it works correctly but after 1 or 2 seconds the image is rolling back in time while my head keep playing and i have to press stop and play to get the correct image again.

How can i resolve this please ? Thanks !

Pierre