I was collecting the apples for a task in the orchard. 2 of the 8 apples had an ambush from three Lunimara. For both of these battles, I was unable to fight.

Visually, the pet who acts first was forward, and in the attack queue*, it showed the icon of the normal element attack (beam) of the third pet in full opacity, and the normal attack (fireball) of the first/second/both pet(s) in a lower opacity underneath.
*by attack queue, I mean the bar at the top of the battle screen that shows the selected action and consumables used during the turn.

I was unable to select an attack, close the attacks menu, or select an enemy to attack. End turn seemed to be selectable though.
I didn't experiment around since I was typing quickly and assumed it was a one time bug, overloaded menu or something.

I was able to use the Run Away function to exit battle.

I believe this is recreatable by having the apple collecting quest, and getting a Lunemara ambush. I will update if I see it again and remember.

Suprisingly early update! I was cleaing Flotsam and had the same issues with the water nymphs.

I was able to finish the battle by manually clicking the attack button, enemy, AND the end turn button. The hotkeys didnt work and the visual error was there until I passed the first turn. It functioned normal after that.

I was unable to trigger the bug again to test if only end turn needs to be clicked instead of using the hot key for it to function. But the hot keys dont work on the first turn.

Two instances on clip.

In the first instance, I discovered that the manual screen clicks work, and the hotkeys function after the first turn.
In the second instance, I am demonstrating that the hotkeys aren't functioning, and discover that manual clicking includes the end turn button.

I have actually reported this bug before, and in my case I just refreshed the page at the start of the battle to make the hotkeys work again. Krin said he'd try to take a look at it, but I can confirm that it's still not working for me either.