So, I'm currently rewatching GoF and got stumped at the first task. In the books Harry outflies the dragon and get's the egg, get's hurt but is fine. In the movie the dragon rips her chain and chases Harry to the castle and nobody does anything. Where are the promised security measures? It's bad enough that the arena aside from the ground is made of wood why is nobody helping Harry? Why did they use such a weak chain? Everyone just sits there dumbfounded until Harry comes back.
And then I started wondering when else the movies just made no sense so, here's a few examples, feel free to add your own
PS:
The trio finds Fluffy because a stair changed it's course instead of running away from Filch in the middle of the night
Hermione staying behind to take Ron back and leaving Harry to face "Snape" (well they thought it was Snape) alone instead of being forced into that descision by there only being one potion to go ahead
CoS:
Hermione using magic in Diagon Alley to fix Harrys glasses instead of Arthur doing so
PoA:
Harry using Lumos at home wth
Harry seeing Peter on the Map.
Not explaining the marauders and Snapes backstory, how th are you supposed to actually comprehend why Snape hates Sirius and Remus so much that he wants them both kissed by Dementors (though to be fair, that is a massive overreaction on his part, even in the books)
Having Snape be consious right after Remus transforms and having him protect the kids, there's no explanation for him just letting the dementors attack Harry and Sirius and waiting until Harry is done casting his super-Patronum
GoF:
As seen above but also
Third task only being a labyrinth with mean hedges instead of being filled with magical creatures. Yes, you can get roped into them but the characters are shown to outrun that, that's not a magical skill
Not showing or telling any of Crouch Jrs. (and Bertha Jorkins) backstory other than "he was sent to Askaban" are we just supposed to make up how he got out and in contact with Voldy?
OotP:
Harry not keeping tabs on the wizarding world through the daily prophet during the summer holidays. And don't say he did, we just didn't see it. In the books Harry was being a bt of a goof by only reading the headlines but the movie Paper is calling Harry a liar on the front page, no subtlety whatsoever and he acts surprised about it at Grimauld Place
Not including any Quidditch or explaining why Harry is not playing that year
Not explaining how and why the Deatheaters knew that Voldys trap had worked (was a stupid plan btw) and that the kids would break into the ministry. Are they just there 24/7 hanging out in hopes that the chosen one breaks in?
HbP:
Can't think of any rn, haven't seen the movie in a hot minute and haven't read the book recently either but
Weird way the film started with Harry and that Muggle girl at the train station and him reading the daily prophet in front of Mugges.
DH:
Flying straight to the burrow instead of a safe house and taking a portkey. It's not a safe hideout, if anyone can follow any of the Potters there.
Not explaining the Voldemort rule, we never got confirmation how the DEs found the trio in London
Ron not having a cover story of being home sick (as the dressed up ghoul) instead of out and about with Harry. That's inviting the bad guys to torture your family
McGonnagal sending the Slytherins to the dungeons because one girl said to catch Harry
Not explaining what fiendfire is, it looks like they threw the diadem into a regular aggressive fire, which makes needing the sword of Gryffindor and Basilisk teeth look like overkill
I'm sure there are more examples but those were the first ones I thought of