In fact using Shift-Return instead of the HTML-Tag
to insert a line break works much better. The described effect doesn't occur if Shift-Return is used.
However, a folder title below the folder icon allows line breaks in order to prevent arbitrary line breaks or to insert a kind of subtitle.This line breaks are ignored in the PREVIOUS or NEXT buttons. If the title is long enough it will be truncated at the right end of the button, Regarding the NEXT-Button a long title so overwrites the folder icon. The widths of those 2 bottons (PREV and NEXT) depend on the length of the litle, i.e. a short title makes a button small in width, a long title makes the button half a page width. It would look nicer if both buttons have the same width.
Not a severe problem, as I already said.