Button in datagridview for each indiviudal record

hey guys i recently made a project but i have a problem with it now and i want some help from you guys ;)

myproject has a DataGridView for Projects ( my project is about Project Time Managements ) with WinForm

I put Start and Stop Button for each Project for tracking Time...

when i press StartButton for any project -- all of the buttons change to stop button

i just want to that record change button.

i will upload my project thank you ( notice + please install ef on it when you run my project )

thank you