Reply to Effect not turning on

Apologies first up if this has been covered in a previous thread.

But I'm having a issue where I've created a single button effect that selects a delay and turns it on a the same time.
All good in theory, but when I push the button, the effect loads, but doesn't turn on till i push it again.

Any ideas?
BTW this only happens when if it's switching from another efx setting.
I'm really hoping there's a simple solution.
Many thanks in advance