Newton Movalpolos Coffer Key does not drop

[Haladir]

For 9 hours today, I have been killing the mobs that should drop the Newton Coffer Key (the mobs on the path to the mine shaft), with TH7 and have yet to receive any coffer key for this zone - Any Input on this matter would be greatly appreciated!

[Alphadeus]

I got a key yesterday, and went back today to try to get another. I got one within 23 kills with no Treasure Hunter.

There are only 7 monsters that drop the key according to the Wiki I used to target for the key. Some of them are scattered within mobs that don't drop the key.

Goblin Junkman
Moblin Aidman
Bugbear Watchman
Bugbear Deathsman
Goblin's Bat (belonging to the Goblin Headman, who isn't listed as dropping the key)
Nightmare Bats
Purgatory Bat

I got the key from a Bugbear Deathsman. Some of the 23 battles were not key-dropping mobs.

Just wanted to confirm the key still drops, at least on Ragnarok.