Search for Warner Bros. animated shorts goes wrong

Back in 2016, I posted a thread about how searching for the most voted animated short films from MGM was going wrong. 

https://www.imdb.com/search/title/?title_type=short&genres=animation&companies=mgm&sort=num_votes,desc

Specifically, the search finds a bunch of Disney cartoons from the mid-1930s which were distributed by United Artists, but which MGM never had any rights to. (MGM did purchase UA in 1981, but UA hadn't had any rights to those Disney cartoons for more than 40 years before then.) 

But it doesn't find any of the cartoons that were distributed by MGM itself during the classic era -- like the Tom and Jerry cartoons directed by Bill Hanna and Joe Barbera, or the various cartoons directed by Tex Avery.

Well, that problem still persists. But now I've done a similar search for Warner Bros.' animated short films:

https://www.imdb.com/search/title/?title_type=short&genres=animation&companies=warner&sort=num_votes,desc

And that search turns up a grand total of 2 shorts: Looney Tunes: Dynamite Dance (2019) and Punch-Drunk Love: Additional Artwork by Jeremy Blake (2003). That's it. There should be about 1,000 Looney Tunes and Merrie Melodies shorts that this search should find -- all the Bugs Bunny, Daffy Duck, Porky Pig, Sylvester, Tweety, Wile E. Coyote, the Road Runner cartoons that Warner Bros. released for decades. 

It's not like Warner Bros. isn't listed by IMDb as a company on those shorts. What's Opera, Doc? (1957) lists nothing but Warner in its company credits: https://www.imdb.com/title/tt0051189/companycredits. Warner Bros. is the production company and twice listed as distributor, while Warner Home Video is listed three times as distributor. Same for Duck Amuck, same for One Froggy Evening ... a search for Warner Bros. cartoons should turn them up, but it doesn't.

Oddly, it's only MGM and Warner Bros. that this search doesn't work for. It works for 20th Century Fox, Sony, Paramount, Universal, and Walt Disney. (DreamWorks didn't exist during the classic era of animation, but a search for their animated shorts still turns up 5 of them from recent years -- more than twice as many as the Warner Bros. search finds.)

So the search problem for MGM not only has not been solved after three years, but it has expanded to Warner Bros. as well.