Yep, they do.The magnets you ordered just suck.
The magnets I linked are rather strong. I just did some testing with two brands I have:
* Option 1
* Option 2 - slightly stronger
Both were able to support the weight of this 64oz flask, with some movement/bouncing . Option 2, using the alternating magnets was able to hold the flask, plus about 6-oz of water, and light movement
The only thing that slightly sucks about option-2, is when you first get the magnets, you have to pry them apart a little, but then they're fine. I think the silicon coatings being compressed into each other for a long time slightly "glues" together.
View attachment 728353
Ordered a pack of Option 2 hopefully they aren't #2.