Trade Window: Invalid channel name

[Faycop]

Describe the bug
I have an error on the trade window. I've setted WIM to show trade channel on a different WIM window but when I leave the city it gives me an error on the WIM window "Invalid channel name" and re-entering the city won't join Trade channel back again.

I have to logout and login and type "/join Trade" to be able to see trade channel again.

To Reproduce
Steps to reproduce the behavior:

1. Enable Trade Chat Window in WIM Options
2. Exit city
3. Re-enter city
4. Trade channel is not re-joined automatically

Expected behavior
When I re-enter in a city I expect to see the trade channel re-joined automatically

Additional context
The bug is very similar to an issue reported in the prat repo: sylvanaar/prat-3-0#114