Yes, tried it just now on a random lesson. If the text was split correctly and no scrolling is needed - than of course you won’t reproduce it. Just open the lesson, and then reduce the height of the browser window for a scroll bar to appear. Then select some words in different places and press space bar.
UPDATE: it happens in incognito mode the same way.
I actually tested it in the same lesson from your screenshot above. Of course I made sure that scrolling is needed before I tested it.
That’s actually the feature that exist in most browsers, Chrome and Firefox both. Space will scroll the text down. To avoid that, just select any word in a text, it will only scroll down if no word is selected.
That’s the problem, it scrolls down when the word is selected. Anyway, if you can’t reproduce the issue, it’s probably something to do with my setup.
Only that I was using LingQ without a problem for half a year already, it makes me wonder why I started to get this issue now. I’ll try to figure out what append.