markings leftover from jamboard uploads

I have been uploading my jamboards to FigJam. After uploading them all I noticed I had random markings all over my slides. They look like leftover pen marks from when I wrote on my jamboards. However all of my jamboards are erased.

Some of them allow me to take all the markings on the page and delete them. Some force me to select each individual mark of which there are tons and delete them individually. As a teacher I do NOT have time for this. And Jamboard expires soon.

Does anyone know a fix so the uploads come out correctly?
Thank you