Here in America eastern European film makers, especially those from the former Soviet Union, are, or were, portrayed as making bizarre and meaningless movies. For example, this clip from the Simpsons; this old SNL Sprockets episode, and another example from the Simpsons.
Is this characterization of their film making based on any truth, or is it fiction.
If they did produce such films, was a tiny portion of their films, about half, or were most of their films like this?
Well modern stuff ain’t always better. ‘A Serbian Film’ comes to mind. Yes that is the title.
The impression leans more heavily toward the bizarre because of the way film festivals and cinematheque style outfits run - the selection favours “significant” or arty films over familiar genre movies. If you are North American and watch a lot of foreign films, you’ll tend to see a weirder slice of those films than are typical based on simple geography.
From over here, what do we know about Czech films? Svankmejer and Menzel.
When I think of German movies, I don’t think of the run-of-the-mill, I think of Die Toten Fische**, which is a Kafka-esque allegory about a guy who spends his days risking his neck down in the sewers with a butterfly net, collecting postage stamps which float by. (For his employer, a fascist and fastidious philatelist. ) Thank you, lifetime of cinematheque subscriptions. Intellectually I know that (by-and-large) most Germans watch more quotidian entertainment, but if you are the sort of person who likes to watch “foreign films” as a category, you’ll find it’s likely to skew weird. 
Back in the day I saw some Czech cartoons that made the Simpsons parody look normal.