When u grind coffee a dusting of very fine coffee grounds cover the outside of the lid. After removing the lid B sure to wipe away this dusting before replacing the lid. The space between the lid and the body opening is very tight. So the dust causes the lid to stick shut.
I don't. But as for the residue left behind, I use a small brush to clean them out after use, then a paper towel with warm water to wipe out the oils that the coffee may have left behind. Hope this helps.
I have not encountered this issue, not even close. My lid opens and closes very easily each time. Sounds like you might have a defective unit. Can't think of any other reason why your issues would occur.