Whenever I attempt to appease the volcano at the altar of snackrifice the volcano erupts anyways if I leave it. I've appease the volcano fully many times and every time the volcano erupts exactly when it would have otherwise once I leave. I've never successfully appeased the volcano and had it stay appeased once I leave. I've tried several times on several maps.
Steps to Reproduce
Enter volcano, appease volcano, leave volcano
Enter volcano, appease volcano, leave volcano