ViewPort fps high but playing fps limited (UE5.7)

Hello everyone,

Hope everyone is doing good.

I found some strange behavior happening in my unreal 5.7 project.
By the using, the foliage is using the new experimental procedural foliage.

When using view port (full screen mode) the fps is high , however when playing the fps is getting limited to 39 40fps, seems its being capped.

Below the printstring of the stat gpu and UNIT, but i couldn’t figure out, whats happening.

Playing:
Noticed low gpu usage when playing

Viewport:

high gpu usage and the fps is highier:

If someone has some advice, please let me know.

Trying to understand whats happening.

Thanks in advance.