Reply to Weird Midi Note Problem in Ableton

Hey guys,
so i just started up a new track, and after like an hour i realized that sound was playing even when the midi note has stopped, and the only way to stop the sound is by stopping the track. Its like this weird sustain that goes on and on. This is a problem I've never encountered before ever. I know its not reverb/etc because i don't have any reverb plugins active the sustain is level and does not decay.

The strange thing is almost EVERY midi track does this - even in different vsts. There's only one that doesn't sustain (Nexus). Also, if i take 1/8th off the last midi note of the clip, it doesn't do the sustain thing.
Its really annoying and i have to constantly automate the clip on/off. Anyone knows why this happens and how to fix it?

Thanks!