What computer operating system is involved? Have you updated 13 to 13.1 yet using an opened project's Help Menu/Updates?
What are the properties of these videos that you are importing into this Premiere Elements project? What is the brand/model/settings for the camera that recorded this video? Was the video recorded from a cell phone, iPad, or any other device that might be recording with a variable frame rate?
What are your computer resources, and what is the size and complexity of the project when the freezing occurs. What specific edits are you doing in the project when you run into the workflow freezing issue?
Is the problem happening in one specific project or in any project that you open, old or new?
Let us start here and then decide what next.
Please consider and supply details.