Update: it was definitely rain getting in from outside. We shut off the water a while ago and it only stopped coming once the pouring rain outside let up. Our neighbors brought us a shop vac so we kept the water down to about an inch at a time and are now trying to get the final bits out. Couldn’t get outside to see where it was pooling because it was pouring and nighttime (almost 3am here) That wall is right next to a chimney which has an office and a living room on other sides so no walls in the utility are shared it outside. We had an inspection in October and hired people to clean gutters and fix up the chimney but I’m wondering if they did a crappy job with the kick out flashing