My left armpit belonged to someone else for a long time after node removal. As arpie says, surgery knocks the nerves around and it can take ages for normal feeling to return. That said, my armpit may have felt sticky but since I coud feel almost nothing, I had no way of knowing. If sensations are significantly altered, you need to be careful with things like hot wax - I could not detect hot or cold in the underarm area for many months. If your other armpit was not surgically treated, and has the same problem, the issue may be a reaction to overall surgery. It'll probably reduce but you may want to consult your surgeon or oncologist, just to be sure. Best wishes.
