Yes, I've experienced this many times with different applications. Some older ERP systems frequently operate like that, where they have a grid that is only recognized by PAD as a single large elements, and no child elements inside it can be captured by PAD.
When this is the case, we usually have to resort to automating such user interfaces using Send keys and image recognition actions, such as Send mouse to image or Wait for image. Send keys is the recommended approach in this case, as it is slightly more stable. Image recognition relies on things like the screen resolution and no pop-ups actually blocking the view.
And still, when you do this, you still need to be aware of the possibility that Send keys may not actually do what you originally intended it to do. For example, if you use a series of {Tab} keys to navigate to a field on a window, it might not get to the correct field if the order of those fields changes, or if something briefly interrupts the flow. Even some lag on the app can make it send the keys to a wrong field/button, if you don't account for it and build in some delays.
So, be very careful when automating user interfaces with keystrokes. Make sure to give it enough time to navigate, and add verification steps that check for windows/elements/images appearing or disappearing to make sure that your keys actually did what they were supposed to do.
