Depth of Field Post-processing in URP leaves square unblurred

[mental zodiac]

I'm using the Depth of Field Post Process effect in URP. For some reason, there's a square in the bottom left corner that doesn't get blurred. Here's a screenshot:

[midnight tundra]

Maybe that whole square (not only the torch) is rendered to depth buffer and is at correct distance to not get any blurring (exactly focus distance away from camera)?