ZBT has encountered a security issue. To be safe, go to your wallet and revoke the authorization. Tap on Assets - tap the first icon at the top right, find Portfolio - tap the second icon at the top right, find the authorization, and locate the ZBT coin below to revoke its authorization. Actually, I used to have a good impression of this coin, as I staked 50u before and received 36 coins, selling them for over 28U, with a unit price of 0.79U. Now it's only 0.08U, having dropped by 90%.