2 IronAxe, nothing like this has been officially recorded yet. Of course, I'll examine other tournaments more closely tomorrow, but from everything I've seen so far, it hasn't happened. So, I associate this with an individual glitch, similar to how a hero sometimes remains in the Castle without troops. If I eventually get a save file to understand which chest is being referred to, it will be clearer.

And I raised this question because if it turns out to be a glitch and it's officially permitted, then many others might glitch later on. So yes, please try to look into this situation more carefully, especially since the player honestly reported such a problem while still in the process of the tournament.
PS. Got the licensed version today — there's an access code for ubi inside. Tomorrow I'll try to figure out the installation of 1.5. Maybe I'll even have time to somehow complete the map :)