For me the first thing that comes to mind is Tales from Earthsea. I don’t think it’s excellent or anything and has plenty of problems but people act like it killed their dog. While it has its problems that have been covered extensively, I think it has a beautiful atmosphere and art.
IMO it would have been better received if it wasn’t advertised as an Earthsea adaptation and was just its own thing.
As I understand it, a couple hundred staff were laid off at the beginning of its final year of production. So a lot of the movie got outsourced instead of made by the people who started the film and did the trailers. Also, more than half the budget was spent before it went into full production. This may partially account for that bizarre discrepancy we had as kids looking at the trailer then seeing the full film.