Hi Eliane,
1. Can you let me know which protocol you are using for signalling links.
2. Whether the links are LSL or HSL.
3. Which type of traffic you are routing.
4. Any specific errors which you are getting on these links as soon as you route the traffic.
I think the error is because of messages which you re receiving in response to your messages send to various destinations for roaming.There is some type of protocol mismatch between them.The best way to find out is to route traffic on single destination at one time and notice that after traffic routing to which destination the links are going down.Then you can speak to technical team of that switch.
OR
you can take support of Ericsson support team.