Piece of Power will expire on changing floors in some dungeon transitions

[Requiett]

In the original game, a Piece of Power or Guardian Acorn powerup would stay in effect while changing floors on a dungeon. I noticed this once in an earlier dungeon and was able to replicate it again when reaching Catfish's Maw (# 5).

From the entrance of the dungeon, 3 screens to the left, there is a set of stairs I entered with a Piece of Power in effect. Both the power up music and the actual sword effect were gone after entering the stairs.

Normally this power-up effect leaves when exiting a dungeon or building, or vice-versa if the power-up was obtained outside. I believe the flag for the stairs was mistaken for an entrance / exit and canceled the power-up.