New Reddit also messes with text selection with unnecessary JS crap. Wherever you select some text, they show an "Embed" button that prevents you from dragging the text to a new tab to perform a web search.
Thankfully this behaviour can be blocked with uBlock Origin by adding these rules:
www.reddit.com##+js(aeld, mousedown, isSelectionOutOfRange)
www.reddit.com##+js(aeld, mouseup, shouldShowButton)