Slot number give 3x? instead of actual number

I have a setup of Shelley stakepool with 2 nodes. 1 nodes is configured as the block producer and the other as relay. Only the relay server is published to the internet, the block producer not.
In the topology file of the relay node I’ve configured the connection to the block producer using the private IP 192.168.x.x. The block producer connects to the relay using the public IP (internet facing)

Although everything seems to work fine I noticed that the on the relay node for the connection to the block producer says slot “???” instead of an actual slot number.
Does anyone know if this is normal behavior or if not any suggestions? Thanks.

Update: it does not make any difference if publishing the block producing node with a public IP. Still the slot number gives “???”