Beginner question - Door rail

Hi, Advice needed.
I’m trying to model a door rail and am unable to run an ovolo edge beyond a certain point.
Being a beginner I’m finding using the correct terminology equally as difficult to explain what I mean!
Please help.

Based on what you show, it looks like you need to select the geometry that overlaps, right click on it, and choose Intersect Faces>With Selection. Then erase the waste.

When I need to model things like this I profile the edge of the rails and the stiles. Then I use Trim from Eneroth Solid Tools or from Bool Tools 2 to cope the ends of the rails to match the stiles.

And if I need full length tenons, I add those to the rails after coping and use Trim again to mortise the stiles.

Thanks for your response Dave.
Stepping into the unknown here but I’ll give it it go!