Boss Battle banner displayed incorrectly



Boss Battle banner (or whatever this thing on the right of the main screen is called) was showing me Calibero and remaining days/hours. But when I strarted Duelyst today, it showed the next boss with a new countdown. At first I thought Calibero battle was a narrow-time limited event, but then I clicked the banner and could choose a deck to fight him. After defeating Calibero, banner now shows next bos with countdaiwn - “Defeated” written under the portrait

Operating System:

Windows 10

System Specs:

Intel® Core™ i5-3570K CPU @ 3.40GHz (4 CPUs)
16384MB RAM
NVIDIA GeForce GTX 1060 6GB

Game Client:

Steam Client