I could not find an official rule that states directly what exactly to do when 2 pawns are face to face. It says that you can jump over it to go it's behind if there are no walls between the opponent and it's behind.
At this point it is not certain if we can also move diagonally whether or not the behind of the opponent is blocked.
Please check the visuals below (red is about to make a move):
In the first one above, red can move diagonally and it does not care if behind of the blue player is blocked or not.
In the second one below, red cannot move diagonally because behind of blue is not blocked by anything (edge, other players, wall).
I have seen both usages but there should be 1 original rule. I do not want to use house rules. This is not directly documented in the original game. What do you think?
The 3rd one is interesting. It may solve the question or add another question.(because this time, the direction of the movement may be a parameter too.. Should diagonal-rule work only while going towards north or not..):