bin is clicked twice on the first click
forge : 1.16.5
mekanism : v10

Could you elaborate on what you mean, as it sounds like your mouse potentially is just dying. Also is this say left clicking to remove items or right click to put items in or what?

When taking out one item
I changed the right click assignment, but it has no effect

I'm flipping the left click and right click assignments

I am unable to reproduce this, have you tried using another mouse?

Yes, but it's still happening