Winbox from LAN to VPN (and internet) not working

Hi everyone

I am a Sophos noob. I manage a lot of Mikrotik routers and make use of Winbox a lot. The routers I manage are all connected by VPN to a cloud hosted router to which my XG is linked by means of an IPSec tunnel. I have done ping tests and traceroutes to the routers and get replies and Winbox is able to authenticate with the routers and opens up but receives no data from the routers I connect to. After a couple of seconds Winbox disconnects and a log entry is written into the firewall log.

This problem occurs via the VPN and over my WAN connection to the router's public interface.

I only have the standard firewall rules plus a couple of port forwards.

Does anyone have an idea of what might be going on here? I need to have this working properly as it is business critical.