The realm will kick everyone out and reset half an hour so a lot is lost

We thought this was a one off situation but it's not. My realm has been resetting itself half an hour when it kicks users off it. This had happened quite a few times since opening my realm. Is there a particular reason or is this something new?

Im only reporting this as each time it's done it we have gone and done stuff and it's either building or going into ancient cities and getting tons of loot. And when it resets it basically makes us lose all that time. And it's very frustrating on me and my users as we all just lose motivation on re doing all the stuff we did that past half an hour.