I actually know what causes this, and it's that the rubber for the button contacts seems to get damaged by the contact cleaner. I disassembled my controllers to replace the sticks cause of drift, and noticed the rubber for the x button was very damaged and there isn't really a way to replace it afaik without having to buy new controllers entirely unless you can figure out how to make your own. This is what they looked like, they ripped when i tried to get a better look at them but you can see that the outer rim of the rubber is kinda melted a little bit.
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