Customer opted for reinstall to resolve the issue. Updating the port steps for future:
1. Stop agent 2. Delete port1691 folder from install area 3. Edit config/sysedge.cf file to change port inside the file and save. 4. Start agent -> New folder with updated port created (I.e. port48280) 5. Stop agent again 6. Copy in sysedge.cf into new port folder from other agent 7. Start Agent
Note - Steps 5-7 are only needed if you want to copy the monitors and configuration from the other agent.