Monkey Archers walk off platforms

What I did: Walked into Ape Atoll

What I expected to happen: See archers on platforms

What actually happened: They walk off their platform and can get attacked with melee.

IDs of related NPCs/items: 1457 Location: id=11051

2009-era source (if relevant): https://runescape.wiki/w/Monkey_Archer?oldid=825787

Screenshots or video:

LIVE SERVER username affected by this issue:

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