Instrument tracks all triggering

[Keeran Williams]

I added an instrument track in. Its a virtual drum kit. Then I added a synth in on a new track. 

When I use my midi keyboard I am hearing the drums triggering and notes being played through the synth plugin.

Anyone know what I've done here? It started doing it a few hours ago but didn't seem to be problem before. Every instrument I add is now playing at the same time. 

[Promidi]

Which version (numerically) of Cakewalk are you using?  The latest is 2020.4 Build 179

Are you sure that input echo is enabled on just the intended instrument track and no others?

To make sure, click on the disable input echo icon on the Mix Module.  Then enable the input echo icon on the specific track.

Also, in preferences | MIDI | Playback and Recording, see if deselecting "Always Echo Current MIDI Track" makes a difference.