CN105 problem with network connection

[ionutm80]

Hi,

I have 3 Mitsubishi units SEZ-M35DA and for each I have already connected a MAC-567IF-E unit on the CN105 port. I have managed to find a CN105 splitter, see picture below so that I can also attach Wemos D1 Mini and control the HVAC locally not through Cloud, however I still need to keep the MAC unit for WAF reasons.

The problems is that once I attached the Wemos D1 on the same splitter it works and gets connected to both the HVAC and MQTT server but the MAC-567IF-E enters into an error state and losses connection to the internet, I cannot longer control the HVAC through Cloud. Once I disconnect the Wemos D1 (which by the way is working great, I can control the HVAC, HAOS integration through MQTT also works) the MAC-567IF-E exits the error state and connects again to the Cloud.

For somebody who knows the schematics of CN105 port, is it somehow allowing only one connection to the internet to be active? Or is it an electric shortage due to Wemos D1 that puts the MAC unit in error state?