Bug with Garuda Hardmode Unable to target invisible boss

I been experience in multiple times not being able to target Garuda in hard mode.
I took screen shot showing problem.
Garuda would become invisible on my screen (still show garuda on enemy list)
and i would be unable to target the boss (invalid target)
i don't know if this is a latency issue or what?
Garuda would reappear when she warps.Usually she disappears during 1st half of the fight.


https://scontent-b-pao.xx.fbcdn.net/...86327365_n.jpg

http://img600.imageshack.us/img600/5750/3vyo.png

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ISP:
Verizon

Type of Internet Connection:
Verizon FIOS

Internet Connection Speed:
15mpbs down / 5 mbps up

Date & Time:
6:20 PM PST and various other times fighting garuda HM

Frequency:
multiple times

Character Name:
Lucky Cat

Race:
Race of your character when the issue occurred.
Miqo'te

World:
Aegis (JP)

Class/Level:
Level 50 Warrior

Area and Coordinates:
Duty Finder Dungeon Garuda Hard Mode (The Howing Eye (Hard))

Party or Solo:
8 people Party

Monster Name:
Garuda

In-Game Time:
About 5-10 min into the fight.

Steps:
See message above

it's a latency + game issue