I also faced a similar issue, the problem was the form was inside a folder and the file .aspx.designer.cs
I had the namespace referencing specifically to that directory; which caused the error to appear in several components:
El nombre no existe en el contexto actual
This in your case, a possible solution is to leave the namespace line of the Members_Jobs.aspx.designer.cs
file specified globally, ie change this
namespace stman.Members {
For this
namespace stman {
It's what helped me solve the problem.
I hope to be helpful