[boost] [git][flyweight] something messed up with master and develop branch

Dear Git connoiseurs: I've realized that my master and develop branches at boostorg/flwight appear collapsed: https://github.com/boostorg/flyweight/network Yet I am seemingly able to treat them separately: commit to develop, test, merge to master etc. The only weird thing is the diagram above and the fact that the commit log in master doesn't have the usual "Merge branch 'develop'" commits: https://github.com/boostorg/flyweight/commits/master Any clue what's going on? Thank you! Joaquín M López Muñoz Telefónica