I’m on Samsung Galaxy S7 - Android 8.
Started a forge on all items, troops, spells, obstacles and towers, only to discover that the cooldown is several days, instead of the max 12h as the event should give.
Edit: Some additional info. I had the BS event banner in the top of the screen with a red animated arrow pointing to it, pressed the banner and pressed the “Let’s get started” button, then a green background with the king & queen appeared, and nothing more. Waited for a few seconds, and backed out from that screen. Tried the same procedure again just to be sure, but with the exactly same result. So maybe that’s the reason, but I’ve never had to “start” the event myself before.
IGN: Kong Lynge - Danish Knights