i been having problems with the editor, specifically with the river tool as it does not seem to make river slit in the desired direction

in this picture i am try to split the river from the blue hex and it not allowing me to do so

the only way it allowed me to connect the river is this way and it looks weird, as i wanted the river to flow from west to east and south, but the split is from south to east/west

in this image it won't allow to make delta end to the river, or make a connect to the river coming from the north