...what is the bug...
Thanks for the info!
For my part, I'll write here what the essence of the bug is: with the Overload skill enabled, the blue player's heroes, when visiting a watering hole, receive +1000 mana points the next day, not for 1 day (as it should be), but permanently. This bug does not always occur, but a temporary rule has been introduced until the bug fix is released for such cases.