About an hour ago I was playing and clicked to start a challenge event level. Screen came up and with searching for connection and then stated connection lost. When I came back online 5 minutes later some of my progress was lost- including filling a raid chest, getting a goblin chest with 100 Valhalla coins, and several completed levels of the challenge event.
Same happened to me. Lost levels from 11 to 14 in the Rare Riddles of Wonderland. Looks like there was some sort of rollback.
This seems odd. I’ve heard of disconnections, but not one that removes past events. You’ll probably need to contact support for assistance on this.