The corner of molding on 2 corners of Pella Slidin Door has pulled out
Your photo looks like it is actually showing your snap-in glazing bead starting to whither a bit. We can help you locate a replacement. Please remove a portion of it from the window and send us some photos of it from an end profile like the diagram below. Make sure to include some measurements.
This doesn't look like vinyl snap in glazing, but rather patio door frame cladding. I don't think you can get this from Pella because it's installed at the factory. You will need to put the old cladding back on using a silicone type sealant. Failing that, you'll have to purchase a new door from Pella. I'm afraid you don't have a lot of options when it comes to this. Sorry we can't offer a better solution.