Severe latency making Darkhold impossible.

Thread Title:
The latency issues in Dzaemel Darkhold are bad to the point of making the Tulurd fight practically impossible. All party members report moving a large distance away from red circles, but still being hit by Firewater. Multiple attempts at the fight over the span of a week show no improvement.

Below is a link to a video I've taken showing what I mean.
here.

ISP:
British Telecom

Type of Internet Connection:
DSL (Ethernet CAT5 connection)

Internet Connection Speed:
ping: 42ms download speed: 4.70mb/s upload speed: 0.35mb/s

Date & Time:
From 7th September onward.

Frequency:
Always

Character Name:
Mir Ain, Lemochu Azraq, T'bohka Wiloh

Race:
all Miqo'te.

World:
Instance server. (World: Typhon.)

Class/Level:
Synced level 46 PLD, WHM, and BRD.

Area and Coordinates:
Dzaemel Darkhold, second boss room.

Party or Solo:
Party, 4 members.

NPC Name:
None.

Monster Name:
Taulurd / Deepvoid Slave.

In-Game Time:
Unsure.

Steps:

Attack Taulurd after buffs
Engage
Wait for room to be sealed
Wait for Deepvoid Slaves to be summoned
Wait for firewater attack
Leave red circle instantly
Get hit by Firewater.
( video showing steps is here.)