Buckling Question

Hi, collegues

I really need your help.
I solve a buckling problem in 2 steps:

Step 1
fix a rod at both ends, make initial strain 1% (normal strain in "X" direction only) and solve a static problem (as an analysis type, solver "Stationary").

Step 2
change "Analysis type" from "Static" to "Linear buckling" and press the button "Restart"
(both steps without "Large deformations")

Question.
The final displasements and energy of deformations doesn't depend on initial strain (like in eigenfreqyency analysis). How could it be possible? Were is my mistake?

Help please.
Thank your for any advice.