Disconnecting immediately after logging in.

Hello, I have three characters and this is the following situation:

Tydis on Asura, my main character can log in but will disconnect straight away so is unusable

Tidismule on Asura, as the name suggests, is my mule, the second character on my Tydis account, can log in fine no problems.

I have another character linked with my SE Account on a seperate POL ID called Myamoomoo that can also log in fine.

So out of three characters the only one that has connection issues is Tydis, is there any reason for this?

First, double check your Account Management to make sure that the subscription for that character is active. Assuming that it is active, I'd try logging in to your mule and call a GM in-game. Explain that you have verified that the sub is active, and ask the GM to move your primary character. The reason I suggest this is because a very, very long time ago, I got disconnected while zoning when servers shut down for maintenance and my location data got corrupted so I was unable to login until I had a GM do that.