Gotta be honest here — on both macOS and Windows I find it extremely hard to click in that one pixel dead zone above the tab. You can see below that I really have to try to click it:
That said, I believe we are working on patching this behavior and/or adjusting the rounded edges to be less…round, among addressing other issues.
Note that the design change was implemented because the old “square” design does not work well at all with tab groups or split view.