Playing 1.15.1, I'm having trouble capturing an Ancient Mummy Matriarch. I can take them alive in battle and they appear in the loot, but when I transfer them to my research base they die because there are "no suitable facilities". I have a prison and an alien containment, and as far as I can see from the resource files the prison should be fine. Is this something fixed in 1.16, or am I missing something obvious?