Last member in party list disappears and reappears (flashes) on leaving duty

Time: 16:52
Frequency: Always
World name: Leviathan
Character name: Cherry Muffin
Retainer name: N/A
NPC name: N/A
Monster name: N/A
Class/Level: BRD60
Party or solo: Party (any size)
In-game time: 7:00AM
Area and coordinates: Any area
Housing: N/A
Steps:
1. Join/form party for any duty in party finder
2. Enter duty, complete (or not) and leave instance
3. Last member in party list disappears, then reappears, then disappears again, then reappears again (a few times) before settling down and staying in the list

This has happened since patch 3.5 for me, is more of a nuisance than anything as it looks like they have left the party, but then they reappear again. It is always the last member in the list (regardless of job, level or server) and happens with any number of members in the party (isn't limited to just 8-member parties)

Connection Specs
- Type of internet connection/provider: BT Business Infinity Premium 73Mbps fibre
- Modem maker/model number: BT Homehub 5

PC Specs
-=-=-=-=- System Information -=-=-=-=-
SYSTEM_OS Windows 10 Home 64-bit (6.2, Build 9200) (14393.rs1_release.161220-1747)
SYSTEM_CPU Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz (8 CPUs), ~3.5GHz
SYSTEM_CORE_NUM SYSTEM_CORE_LOGIC 8 SYSTEM_CORE_PHYSICS 4
SYSTEM_BIOS BIOS Date: 04/10/13 20:50:54 Ver: 04.06.05
SYSTEM_LANGUAGE English (Regional Setting: English)
SYSTEM_MEMORY 16297.844MB
SYSTEM_VIRTUAL_MEMORY 2047.875MB
SYSTEM_PAGE_FILE 24297.844MB
SYSTEM_STORAGE C:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 237.936GB SYSTEM_FREEDISC_SPACE 41.780GB
SYSTEM_STORAGE D:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 1863.015GB SYSTEM_FREEDISC_SPACE 678.541GB
SYSTEM_STORAGE G:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 476.937GB SYSTEM_FREEDISC_SPACE 441.041GB
SYSTEM_DIRECTX_VERSION DirectX 12
SYSTEM_GRAPHICS NVIDIA GeForce GTX TITAN
SYSTEM_GRAPHICS_DEVICE \\.\DISPLAY1
SYSTEM_GRAPHICS_CHIP GeForce GTX TITAN
SYSTEM_GRAPHICS_MAKER NVIDIA
SYSTEM_GRAPHICS_VRAM 3072.000 MB
SYSTEM_GRAPHICS_SHARED_VRAM 1023.938 MB
SYSTEM_GRAPHICS_DAC Integrated RAMDAC
SYSTEM_GRAPHICS_DISPLAY_MODE 1920 x 1080 (32 bit) (60Hz)
SYSTEM_GRAPHICS_DRIVER C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_02838dee03d82b94\nvd3dumx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_02838dee03d82b94\nvwgf2umx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_02838dee03d82b94\nvwgf2umx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_02838dee03d82b94\nvwgf2umx.dll
SYSTEM_GRAPHICS_DRIVER_VERSION 21.21.0013.7849
SYSTEM_GRAPHICS_DRIVER_DATE 1/20/2017 00:00:00
SYSTEM_GRAPHICS_DRIVER_LANGUAGE English
3.0
SYSTEM_GRAPHICS_PIXEL_SHADER 3.0
SYSTEM_GRAPHICS_VERTEX_TEXTURE SYSTEM_SUPPORT
SYSTEM_SOUND Speakers (Realtek High Definition Audio)
SYSTEM_SOUND_DEVICE_ID {E63926AE-43B2-4B49-B7EC-A6569B95B9F6}
SYSTEM_SOUND_DEVICE_NAME RTKVHD64.sys
SYSTEM_SOUND_DRIVER_VERSION 6.00.0001.6849
SYSTEM_SOUND_DRIVER_LANGUAGE English
SYSTEM_SOUND_DRIVER_DATE 2/26/2013 00:00:00
SYSTEM_SOUND LCD TV-4 (NVIDIA High Definition Audio)
SYSTEM_SOUND_DEVICE_ID {F8AB39CA-CC72-435C-9998-32905236F54F}
SYSTEM_SOUND_DEVICE_NAME nvhda64v.sys
SYSTEM_SOUND_DRIVER_VERSION 1.03.0034.0021
SYSTEM_SOUND_DRIVER_LANGUAGE English
SYSTEM_SOUND_DRIVER_DATE 1/12/2017 00:00:00
SYSTEM_INPUT {6F1D2B60-D5A0-11CF-BFC7444553540000}
SYSTEM_INPUT_NAME Mouse
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 3 SYSTEM_GAMEPAD_BUTTON 8 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {6F1D2B61-D5A0-11CF-BFC7444553540000}
SYSTEM_INPUT_NAME Keyboard
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 128 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {FC609680-FAB1-11E2-8001444553540000}
SYSTEM_INPUT_NAME Logitech G710 Keyboard
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 7 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {29447A60-6373-11E4-8001444553540000}
SYSTEM_INPUT_NAME XBOX 360 For Windows (Controller)
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 5 SYSTEM_GAMEPAD_BUTTON 10 SYSTEM_GAMEPAD_FOV 1
SYSTEM_INPUT {FD5CF7E0-FAB1-11E2-8002444553540000}
SYSTEM_INPUT_NAME Logitech G710 Keyboard
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {8351D680-E96A-11E2-8001444553540000}
SYSTEM_INPUT_NAME Gaming Mouse G600
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {672DC860-2EA6-11E4-8001444553540000}
SYSTEM_INPUT_NAME Razer Nostromo
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 6 SYSTEM_GAMEPAD_BUTTON 24 SYSTEM_GAMEPAD_FOV 1

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