Is it normal the butter have started smell stronger

The brand of butter we always buy (a salted butter) have started to smell stronger than usual. I dont know what this means. I noticed it two months ago as it smelled really strong and then we threw it out bought a new package same kind which was fine. Now the new package I opened today it smells. It says the butter expires next month but I think that its not good and I dont want to eat it personally. Im not sure how to explain the smell except its kinda dull. Its not sour but rather stale, almost like mold... Except there is no mold in it of course and it looks right. Maybe I am just overreacting. Ive noticed the difference in that usually it has no scent, or its very vague. Then other times a staleness hits me when I sniff it. Another thing i've noticed is the expiration date on the packages is way shorter nowadays than usual and I am wondering if that means that the stores are putting out old packages that only has a month left before expiring. Is normal for butter to have a smell or im paying too much attention to subtle differences between packages?? Its not a sour smell after all and the butter looks fine and has normal texture.
Maybe I am crazy. Its a shame to throw away butter which looks fine when butter is expensive. Then again last year accidently ate expired butter for a week and obviously there were no signs except the taste was extremely vaguely different and then later mild nausea so who knows. Completely new just opened butter shouldnt smell though.