TIMELINE IS MOVING WHEN I CLICK ON A GREY AREA,

[pattyannlewis@yahoo.com]

I'm working with Premier Elements 2021 On my Mac editing a video. When I'm editing within the timeline...If I move my cursor to a grey area, either the editing feature options on right OR the video or audio rows on left...The timeline starts moving to the right and out of sight.  I feel I accidentally changed something to cause this to start happening just a few nights ago.  Never had done this before.  

Please help.