One of my forms is extremly slow when adding, any help?

That form is specially slow in one view. Then, when I want to add a new concept in that view and I click on "Add", It takes around 20-30 seconds to open the Add Form.

Please, I need any help about that. I tried deleting all the "On load" code and it still remains in the same way.

Any more ideas?

Thanks a lot.

Sergio Galiano