The answers will be in the details.
What version of Premiere Elements, and what computer operating system?
What are the properties of your source media besides the frame rate of 60 progressive frames per second - video compression, audio compression, frame size, frame rate, interlaced or progressive, file extension, pixel aspect ratio? Please confirm that your video frame rate is 60p and not 60i.
What are you (manually) or the project (automatically) setting as the project preset to match the properties of those source media?
What is your intended export for the "60fps" Timeline content - export to file saved to the computer hard drive or a burn to disc end product? Or, have you gotten to export yet? Are you problems to date only in the Edit area monitor previewing?
Let us start here and then we can decide what next based on the details in your reply.
Any questions about the questions, please do not hesitate to ask.