First of all I must say that all the tests I did in the office yesterday to synchronize the BR1 through the speedfusion were satisfactory. The synchronization was successful.
The problem appears in a production network where the BR1 has the following Wi-Fi WAN configuration:
It seems that it tries to reach the ntp server over the Wi-Fi WAN interface and ignores the following outbound rule:
In the office it worked fine but probably something is missing in the configuration for that Wi-Fi WAN interface.
Thank you for your help!
Support Ticket #777271