What has recently changed on your site as far as plugins/updates etc? If you updated the theme files, did you used to have customization to those files that changed the way your catalog page would normally look?
In the WooCommerce options, do you have anything checked in Catalog>Show subcategories?
Yes thanks. It was in the show subcategory options . Someone else must have changed the boxes there. I had looked there and it lookeed right. I hadn’t realised that subcategories also meant categories.