Kamasa Vaults changed into Vaal City & Molten Vault?

Hello everyone.

Couple days ago I did some Kamasa Vaults near my Stone Citadel and got a lovely Headhunter out those vaults (lucky) Had to sadly share this with my 2 buddies cuz they were tagging along and made them happy.

But then I was happy cuz it was my very first Headhunter and went searching for these Stone Citadels and found another one with 3 surrounded Kamasa Vaults but I was tired and went to bed to do them today. But Now all 3 Kamasa Vaults changed into Vaal City > Molten Vault > Vaal City. So i'm shocked, what is going on?

Even those I did before called all 3 Kamasa Vaults changed into Vaal City > Molten Vault > Vaal City.

Greetings SummonBetsySummon