Trying to model chest.Problem with mesh

[Project_J-DogS1994]

I’m trying to make a treasure chest in blender. I was working on the metal rings that wrap around the led of the treasure chest when I stumbled on a problem with the mesh. Here’s my problem in this screenshot.

The problem only happens when I delete the bottom half. And here is my blend file https://pasteall.org/blend/eeb55cc003f24288b1012da0e63ce90e

edited) I opened the blend file again and I found out that the normals were messed up. and pressing Shift N don’t help.

[Fowl]

You deleted the bottom but not the side polygon.

[Fowl]

Also use bisect at your mirror modifier or you will have a double geometry

Then as you wrote, flip the wrong normals and the model will be ok