SFP link and routing

We have multiple MikroTik SXTs connecting to a PowerBox Pro (Managed by CAPSMAN on this device)
The Power Box Pro has an SFP connection to a RB260GSP
The IP Subnet is the same all the way from AP to the RB260GSP

PowerBox can manage the APs. Computer connected to the switch is can ping APs and powerbox
PowerBox can ping APs but not the RB260GSP
PowerBox can ping Server on same subnet connected to the RB260GSP
Server and cannot ping APs but can ping the PowerBox
Devices connected can connect to the server and upload files

Currently Power Box is set up with a bridge, all eth ports slaved to one eth port and the SFP port is in the port list under the bridge but cannot be slaved.
Question:
How can we get full data connection and communication to work across the SFP to allow for CAPSMAN to manage Mikrotik devices connected to both sides of the SFP