[Spoilers] Have 139/140 Collectibles, 75/78 clothing?, or a Missing Broom? Here's your Problem.

[Sovereign]

This was something that was bothering me for a while as well. Although every region, Including Hogwarts and Hogsmeade, was done, I still had no clue where to get the last items for the collection. Every place was fully completed, and nothing was left to be done.

Turns out, I was panicking for the wrong reason. There's no collectibles tied to main story iirc. It's actually just the two collectible objectives that just...don't show up on the progression screen for some reason: Butterflies and Battle Arenas.

I have no idea why they thought this would be a good idea, since that would mean that you would have to scour the map up and down in full for butterflies praying you got them all, rather than it telling you how many there are in a region. Like landing platforms (to be fair, I don't know why they exist either.) There's no shame in checking a guide for them.

In terms of Battle arenas, there's only 2 (3 if you have Deluxe / Dark Arts). Make sure to do them all for the collectibles. You're free to do these whenever you feel like, and you can plow through them late game very easily. Don't be afraid of the Dark Arts one, too. They just worded it very poorly.

As for brooms, check your merchants. 3 of them are tied to merchants throughout the Highlands, but one is tied directly to a quest that's extremely forgettable. Once you do that quest, just look in the center of Hogwarts Valley. He should be dead center.

Hope this helps!