You probably can change z-index of the title in the user stylesheet, let me know if you cannot do it on your own, you need to know CSS and how to find the title element in the developer tools, and then set something like input.title-input { z-index: -1000 !important; }. Either way, it doesn't seem to be a bug.
Not a bug, but honestly, this is one of the major annoyances when using Joplin on smaller screens. To overcome it, I usually put the same text as in the title in an h1 element at the top of the actual note, as otherwise I've just got no idea what the full title is.
Thanks for the tip... In fact with no plugin at all, the line is clean on my 14' laptop... So on one hand plugins are welcome and in the other hand, there's a graphical price to pay it seems...
