Unable to log into the game on a specific character

[Sylvaria]

- I forgot to mention that I am playing on the Windows platform.
- Wired connection.
- Only the Discord chat program running with the game.
- Frequency at which error occurs: Every time I try to use my main character.
- Time of day this usually occurs: Every time I try to use my main character.
- Everything you have tried to resolve the issue: relaunching the game, logging in on an alt, using a VPN.