Keep your weight back toward your heels a bit longer during the pull.
Push the knees out a bit more in the start and first pull to help get them out of the way - then try to keep them back a bit longer, until the bar is higher on the thigh. That is, wait longer to explode.
Push w the legs a split second longer as you extend the hips. Pull the elbows up and out more as you transition under the bar - your arms are stiff so the bar bounces forward off your hips.