Bayern Munich coach Julian Nagelsmann finally returned to former club Hoffenheim in front of fans on Saturday but was left frustrated as his Bundesliga leaders were held to a 1-1 draw. Robert Lewandowski’s 29th of the season on the stroke of half-time rescued a point for Bayern, who had trailed to Christoph Baumgartner’s opener, but they will wonder just how they didn’t win. Thomas Müller, twice, and Lewandowski netted only to be denied by offside flags, Serge Gnabry hit the post and Müller had a goal-bound shot blocked on the line amid intense pressure. Hoffenheim also had their moments thoug…