HDMI requires the source-cable-splitter-cable-display to all be compliant with the standard. If one is off it will sometimes not work with a combination of other cables and components. A 25m HDMI cable can be very tricky. They didn't really think about long cable when HDMI was designed so we have been going crazy with problems like this.
Does the problem happen when you don't use the active splitter? If not then try a better distribution amp.
You could also try an HDMI booster. https/www.hdtvsupply.com/hdmiextenders.html