FindControl won't find my dynamically added UserControl

Question

I'm working on a project where the page load certain controls depending on the index available. The loading occurs in the page load where the method PopulateSearchField is called.

Within this method, all the UserControl are added on the page using : Page.LoadControl("path");

The page load and all the required controls are on the page. My problem is when the user click on the Search button the event is triggered and a query is built based on the user input int those controls. Unfortunately, the method isn't able to produce a proper query as it is unable to find any of the controls on the page.

With a temporary ControlCollection variable, I've been able to see that the number of controls on my page is 3 when it should be something from 4 to 10. Those 3 controls in the collection are the static label and buttons on the page.

I don't know if something is wrong with the code or if it's a page cycle problem as this solution used to work on framework 1.1. Yeah, I know this isn't the best thing to do so, but they did it this way and I gotta make it work.

I'm not sure if it is the migration that has caused the problem or not.

Thanks a lot, David!