I am not on mobile. It all boils down to the way decade old convetions/expectations are broken.

The things that look like buttons (and are spans in the html code, not even anchors!) trigger non-local transitions (the left panel thing) when hovered... and they close the opened panel when clicked, so if I move my mouse to click on it the end result is a panel that flashes.

I need to keep ignoring the usual button affordance of being clicked and force myself to think they are tiggered on hover.

If this isn't bad UX I don't kown what it is.