I've made 2 different characters and I've encountered this bug where Sanctuary simply will not store surplus food and water in the workshop. It will work (less than the mathematical amount such as 15 settlers with 40 water but I get 10 or so in my workshop per day) but only if you remove the purified water from your workshop first. I've stored the water in a container next to my workshop and I wait until it gives more water. Then I take it out of the workshop and place the water in the container. So far this is the only way for me to farm water that should be automatically added to my workshop. Also, surplus food doesn't seem to work whatsoever. My other settlement seems to work fine, it's only Sanctuary that I'm pretty sure this glitch is effecting but Sanctuary has a river in it and this prevents me from string large amounts of water for supplies or selling for caps. Is anyone else having this problem or willing to test out if their Sanctuary doesn't store any more water once you've put the water into the workshop?