2 updates ago the named dragons stopped dropping oils for me. At first I wasn't paying enough attention to see if it was always or random. I started paying attention after the last update, and have not had an oil drop since. These dragons hit harder, and take a lot more time to kill. Getting less reward for a kill is an insult.
The release notes said something about an enhancement to the hearty charm. What actually has happened is definitely a bug.
When Ninjago dropped the hearty would charge up your shields to the 500 shield cap. The uncommon charged at 80 HP every 10 seconds, and the rare recharged at 120 hp per second. If equipped with a regen, the charging happed continuously. Without a regen equipped you had to eat to get each charge. In my opinion the charm was over powered by letting you charge to 500, but was great early game, until you get an Earth scroll.
Now the charm will charge to 80/120 and stop. When you take damage it does not recharge back up to 80/120 until your main health takes a hit. I did have an uncommon one go to 160, 2 charges when I started a new session the charm game a fresh charge at the start of the session. I don't know what your intentions were with this charm, but at the very least it should recharge back to its cap after an interval of not taking damage. If it has a new cap of 80/120 that is a fair rebalance, but not recharging until you main health is hit takes away any utility for the charm.