Clicking on folder in sidebar opens it in new window

I have a frustrating issue with TotalFinder on a Mojave machine. I have the Visor going, almost always in Dual mode. I’ve got the desired folder on one side in view, and I click the sidebar to open the folder that I want to see on the other side of the Dual mode window. But instead of just navigating to the folder that I clicked on in the sidebar, TotalFinder often opens a brand new window. But I didn’t want it in a separate window! This is the only machine that has this behavior. I’ve tried uninstall/reinstall, but still have this issue. It seems to do it the first time I click on a sidebar folder. If I subsequently click the same sidebar item again, it just opens up the folder in the active window as expected.