in this game i am only allowed to move from 5 to 4 (sending his piece to the bar) . after that i cant make another move as i will have a piece on the bar as well (cloning gammon)

in this case i think it should be allowed for me to move a piece from 3 to 2 as well .. that way i cant move my 4-die .. but if i make the move which is allowed right now, then i cant move my 4-die either

is this a bug ? or is this supposed to be this way ?