This one is strange as it’s inconsistent. I often notice if I reset my app and continue from an existing lesson, I’ll experience it less, but it “feels” like it happens always on the very first time I open up the app after closing it or starting a new lesson.
It’s similar to this post except for the dictionary entries.
This might also be a cause of the crashing. I notice it happens way more often in the latest update opposed to the prior iOS version of LingQ.