DEbugging in vb.net

Hi ,
when i add some new code in vb.net and do a F5 or build the solution and run it it does not recoginize the new code . if i shutdown visual studio and open the entire solution again then it recoginzes the code is there a setting or something that i am missing .

Did you try to do Rebuild or just Build?

I have tried both , none of them work