Welcome to the forum.
If you are talking about when the slide is in, then the floor WILL be raised above the rest of the floor. If is designed to be flat when the slide is fully out. As schled1967 has said, check the top of the slide for something keeping the top of the slide from coming in all the way. If you have the information from the slide frame manufacturer, check all the attaching bolts, screws and lag screws, for being tight. There are adjusting bolts for slide alignment, but unless something is loose, it should not have changed.
Good luck and let us know what you find. Last resort would be a dealer, or on site RV repair person.
Wildmanbaker