Icons missing/changed when switching back to the default desktop environment from KDE Plasma on Ubuntu 20.10

So I have an Ubuntu and Windows dual-boot on my computer, and I recently installed KDE Plasma (using sudo apt install kde-plasma-desktop) as another desktop environment I could use. I switched over to it for a while and decided to come back to the one labeled “Ubuntu” on the login screen. After logging back in I noticed that a lot of the icons have been set to the ones in KDE Plasma. I’ve tried to change them back using GNOME Tweaks and changing the icons pack, but that really on fixes the one for LibreOffice and a few others. The Ubuntu Software Center’s icon is the default application icon or a transparent square no matter what and a lot of the apps that were included in the system have been changed and I can’t seem to get them back to default. I’m still somewhat new to Ubuntu, so the answer might be really obvious.