After a complex troubleshooting with our suppliers , we didn't find any wrong config nor defect hardware.
A switchover on the backup routing-engine resolved the issue.
We performed a second switchover to determine if the routing-engine was defect but everything went up.
So the situation is normal (primary routing engine) and everything is working fine again.
We are waiting the analysis by our supplier of the collected core dumps and logs to identify the root cause.
More details will follow and an Incident report will be provided as of next week.
06/11/2018 18:30