Clicking noise only when handlebars are straight?

I have this bike on my indoor trainer. Began to notice this noise and for some reason turned the handlebars and it stops. Doesn't matter the gradient or anything. Completely gone. I straighten them out again, clicking returns no matter what. Anyone ever experience this or clues as to a potential solution before I put it back together and take it to the shop?

It also stops completely, even if handlebars are straight, when I bend down while pedaling as if i want to put my ear next to the crankset/listen for the sounds source down there.