Weird Sensor problem

[Mistahbrock]

Replying to myself, I narrowed down the error to the mitras serial connector, that is, if I pull it out of the mitras splitter the PH probe acts normal, and when I reinsert the plug into the splitter, PH reading rises to the sky ( from 7.6 to 9.48)

1. this is weird as there is not connection in the water from the LED bar og splitter.
2. it's also weird that it started now, three days ago there was no problem, whatsoever.