Slow rendering when adding usercontrol to panel

[C# Programming]

I have a usercontrol with many controls (labels, textboxes, etc...). When I try to add this usercontrol to a panel, the rendering of the usercontrol is slow. You can see controls rendering when the control is added to the panel. I have tried to the SuspendLayout/ResumeLayout of the usercontrol, panel as well as the form itself, but you can still see the rendering.

How do I stop this from happening?

Thanks in advance.