You select ‘both layers’ so you can see both sides clearly, and in ‘both layers’ top traces are yellow and bottom are orange. Then you pull parts onto the top with it set on ‘view from above’ so they are placed on the top. If you look your parts are faint, so they are on the bottom because you are looking down from the top.
Just export it ‘for production’ and you will see parts and traces on the bottom.