I’m on OSX Mojave running v10.0.15 with a logitech mouse and have double clicking issues. But this issue was in v9 for me as well. I think it’s just bad clunky coding from Steinberg in my opinion. For example if I select the media tab in the right zone then select the file browser any folder that I double click on DOES NOT open. I can double click on as many folders as I want but none open. The solution (and why the coding is clunky or poorly written) is that you have to single click on a folder to highlight it then double click it to open it. Very bizarre behavior in my opinion. Basic stuff like this is very frustrating and is the reason I moved over to Reaper. The Media Explorer and Project Bay in Reaper just makes sense and is so fast and easy to work with compared to Cubase in my opinion. I really wish Steinberg would take the time to look at and FIX the simple design flaws of their DAW that just don’t make sense like the double click issue. Other frustrating examples that come to mind are not being able to resize the Track Visibility window in the left zone (everything past 10-15 characters is cut off) and why in 2019 is it so hard to add a “Project Pool” tab in the right zone? Rant over… back to super customizable and super fast workflow Reaper.