cannot connect to WorldServer error message: CONNECTION TO SERVER COULD NOT BE ESTABLISHED RESPONSE IS NOT A WELLFORMED XML

I am working with Trados 2017. Client has recently informed that the server address has changed.

I tried to connect as usual with the new given server address and the log-in data. And I get the above message. 

in this link the issue is described: https://gateway.sdl.com/apex/communityknowledge?articleName=000004354

The explanation given there is: 

This happens after WorldServer has been upgraded from version 10.4.x to version 11.0 or higher even if the connection worked before.
 
Root Cause
The Server Address needs to be updated in the general.properties file. The url_of_origin value in the general.properties file was not changed during the upgrade.
Resolution
To permanently fix this issue, the url_of_origin in the general.properties file needs to be updated to change from '<url>/ws' to '<url>/ws-legacy'. On the server where WorldServer is installed, find the general.properties file. Open it and update the Server Address next to the url_of_original property to change from:
 
url_of_origin=xxxxxx.sdlproducts.com:ws/services
to
url_of_origin=xxxxxx.sdlproducts.com:ws-legacy/services

What is strange, is my new server address follows the mentioned pattern: ws-legacy/services. So the root given there, does not apply. I do not know how to solve this, as the workaround mentioned here refers to the upload of a return package. But I am at the stage, where I cannot start my work as I cannot connect to the TMs in the World server. You can help?

Thanks in advance!