I watered my cactus about a week ago and I saw it today and it’s completely sunken in. It’s not mushy and it’s still decently green under the spines from what I can tell. Im giving it a long soak because I believe this is caused by dehydration but I watered it just last week. Could it be hydrophobic soil or root rot? It’s always been a weird plant with a lot of problems but i’ve managed to keep it alive for a few years and hope I can get it back!

