Today we've released UTM 9.702. The release will be rolled out in phases.
In phase 1 you can download the update package from our download server, in phase 2 we will spread it via our Up2Date servers.
SG135 / Firmware version: 9.702-1 / RED 15w
When RED is in Operation mode: Transparent / Split, a route is not created in the Sophos SG routing table to get back to the source network (behind the RED).
A standard static route being created, resolves the issue - places a route in the routing table and connection is now working. example;
192.168.1.0/24 -> Interface RED (reds1)