When trying to select the background to make it invisible, when selecting the area to delete, the system overcompensates and removes more area than what is selected. It also end up striating lines throughout the image. I uninstalled the program and reinstalled, and it initially worked a bit better, but then reverted back to having the same issue. I've never had this issue previously and I usually got the results I needed until now.
I am not exactly sure what problem you are describing. What OS and version of Elements are you using?
In your attached screenshot, I see the edges of the medal that have been removed. But it is impossible to tell whether that is a problem caused by Elements or by you as the user not paying enough attention to detail. If you show us the original file and a copy made after the deletion, we may be able to offer you some guidance.
We also need to know what tool(s) you are using to make the selection. If you are using one of the automatic tools such as the Replace Background Guided Edit or the Select Subject option in the Selection tools, it will not necessarily be perfect, but the initial selection can be modified or refined in many ways.