I downloaded Kdenlive 19.08.0 today and when I went into the editor and put in a video and played it, there was a constant very loud clicking playing the whole time. I rendered a segment just to see if the clicking would appear in the render but it didn't. Any time there would be sound (i.e. clicking on the timeline, dragging through it, or playing the video in the editor) the clicking noise would be playing. The noise played regardless of whether there was any audio or not. I tried an older version of Kdenlive which is my go-to every time a newer version of Kdenlive had an issue for me and the clicking was there too. I recently got a new computer and never encountered this issue on any other computer. It is a Dell G3 with Nvidia and Intel i7 if that matters.
Edit: 19.08.0 crashes 100% of the time during render. I don't know why it worked the first time. But I really would like a solution to fix the clicking because I think it might share the same cause as with my older version. I looked but I can't find a version number anywhere and I renamed the folder a long time ago.

the clicking sound on preview mode is related to the impossibility to render on real time the video.. it's very annoying (but if i remember well this happens from ages..)
usually changing the TRACK COMPOSITING from HIGH QUALITY to PREVIEW reduces the clicking... if you have already "preview" mode selected i think that you have to wait some fix to audio preview... ( this need time )