Dimensional Prison (treasure chests?)

[Prajna]

One aspect I love the most about Exe Create games is that anything of importance can't be permanently missed, which is the reason why one-time-only areas in Exe Create games don't contain treasure chests.

The "Dimensional Prison" is the sole one-time-only area in "Knights of Grayfang"; it doesn't feature random encounters (battles) and there aren't any treasure chests (seemingly). Yet: If you use the "Treasure Searcher" item while being inside the "Dimensional Prison", the game will say that there are 2 unopened treasure chests left (PC version).

Anyone who has already reached this area towards the end of the game can probably tell that the area's layout doesn't leave any room for hidden treasure chests. Also, I bumped into every edge, but this area - as the game in general - doesn't contain any secret passages.

That leaves the question: Did anyone discover these 2 treasure chests? Or are they simply the product of a "Treasure Searcher"-related bug?