House was underpinned a few months back. Very dry clay underneath. The winter rains have started. We have a horizontal crack appearing at the corner of our scullery door 5 months on. Would this be due to settlement or is the underpinning questionable. Any engineers or builders with any advice would be appreciated. Our builder thinks he did an amazing job and it should just be filled and watched but I believe it’s on the move and am quite concerned.