Need help including 240 FPS shot video in my project

I'm using Adobe Premiere Elements 2020 and I have a very fast computer which I built earlier this year with AMD Ryzen 7 2700X Eight Core Processor at 3.7 Ghz, with 32 GB RAM.  I shot some GoPro video at 240 FPS to create slow motion and when I try to import it into PE it appears to improt and it will appear with the first frame image and sometimes it will even play for a second or two at normal speed, with normal speed audio, but when I try to render the video, or try to make adjustments using the adjustments tools it will not work.  If I go in and adjust the Time Stretch the video extends out on the time line the appropriate amount, but when I click play the time indicator moves and the clock showing where I am in the video changes but no image appears.  Is there something I need to do to prepare the clip before importing it, or some driver that I need?  I am perplexed and would really appreciate some help.  Thank you so much for any help in advance.