Kubuntu - Strange Copy-Paste behaviour after upgrade to 20.04

I recently upgraded from 18.04 to 20.04 with Kubuntu. I had to delete Python2 to do it, but it worked. However, since the update, something strange is occuring with the copy paste function. A piece of copied text can be pasted into an empty place; however, if the text is being pasted in replacement of other text, however, it instead copies the text being highlighted! For example, say I copy hello. If I paste it into an empty text field, I get hello. However, if I copy world, then highlight hello and try to paste it there, it will instead copy the text hello instead, meaning that every paste after that will just be hello! What could be causing this strange behaviour? The keyboard shortcuts look correct...