A linkshell vanished from my in-game list, however I can still access its Lodestone forum, and others still see me online as a member in it.
The linkshell that vanished was one I had set at the time. It goes by the name Moogle Cake.
Pictures can explain it best.
So at this point it seems I can hear what's being said, but the icon indicating the linkshell is set isn't there in both log and menu. I input the line shown, and it didn't go through to any linkshell.
I'm still able to receive messages sent in Moogle Cake at this point.
From this point on, it's gone and I can't hear messages.
Apparently I'm still in the linkshell.
The line here is in response to:
[6]<Halabel Tia> still says your online in mooglecake
ISP: CenturyLink
Type of Internet Connection: DSL
Internet Connection Speed: 20,127/4,570 Kbps
Date & Time: -7:00 UTC. The pictures are marked with the time. It probably started around 11PM PST on the fifth of January.
Frequency: Once, but its effects persist.
Character Name: Maki Amiyuki
Race: Female Plainsfolk
World: Besaid
Class/Level: I don't know what it was at time of occurrence.
Area and Coordinates: Possibly the Crystaliers Ward.
Party or Solo: I was in a party. There were no members in it later when I noticed the issue. I don't know what happened, but it had been falling apart after finishing with Primal runs.
NPC Name: None, or possibly Ul'dah's local leve dealer, leve NPCs, or even my retainers within the Crystaliers Ward.
Monster Name: None, or possibly the Moogle Primal.
In-Game Time: Before the time shown in the first screenshot. (1/27, 22:39)
Steps: I was in a party fighting the Moogle Primal and it was fine, then some time after the party started falling apart I returned to Ul'dah, picked up some leves, crafted, then noticed this.
Edit:
So I came back hours later, and it was back.
I don't know if it fixed with time, or required me to reboot my computer. Re-logging and restarting the game entirely didn't work for me earlier.