Dear Moustafa,
Absolutely there is an explanation.
There is an explanation for almost everything, at least everything in the super-simple mostly predictable world ofdigital computers.
However, I do not yet quite know exactly what your question is.
Can you please describe more precisely what behaviour you are observing, what behaviour you are expecting, and what the difference is?
What exact buttons are you talking about, and what is the context in which you click them?
I guess and it rather sounds as if you have implemented support for F1 help and pointed it to your specific add-in help pages?
Thank you!
Best regards,
Jeremy