If the final step is taken as the player jumps a ledge in an area with a fourth warp, when returning to that area, the player may be able to walk through walls. If it is made while the player is spinning, the player will always be spinning while walking, even if this occurs in an area from which it is impossible to enter Glitch City, such as Viridian City.
If the player has one Pokémon in the party that is poisoned, when it faints, the player will appear in front of a Pokémon Center. This makes areas such as Cerulean Cave and Indigo Plateau accessible earlier than normal. The glitch is deactivated once a building is entered.
Fishing or pressing the start button while in Glitch City to bring up the menu often changes the appearance of the glitched terrain. This is sometimes permanent for the remainder of the time spent in Glitch City, and will at times change all of the tiles into water tiles.
The glitch you encountered wasn't really a known one based on this website, unless it's a new one. Other wise, it's just a real gltich
Hope this helps!