Hi,
I have the same behavior with my Neuron S103 using Codesys programming tool.
RUN LED is 2 s on/off
I can download a program to the plc and switch it to Run mode but I/O are not refreshed.
I can see a Red triangle just before the Unipi Relays.
Let me know how i can share my project.
Let me know if you need additional information.