No not really just like irl your setup would be as follows from strongest to weakest , Rod , Line , ( leader if you have one on ) reel.
Your reel is the strongest component and rods thake the brunt of the strain so even if you rod is only just heavier than your line as in your gear your rod is going to take all that pressure.
The only way to stop that happening with a setup like yours is to be careful on the drag setting as your reel is 3.5KG stronger than your rod.
You can fish with a setup like that but awareness of you drag setting is needed as too much drag will kill your rod on a setup like this, this would also be the case irl too.
I don't think this is the games fault or a bug I do think its a user fault and the game is not to blame here.
Your rod is 5.5KG
Your line is 5.4KG
Your Reel is 9KG
and your leader was 11.6KG
This setup is a disaster waiting to happen even in real life you would not fish this way.
The game saw your line and bypassed the leader the problem was your line was only 0.1KG weaker than your rod as I said before your rod takes all the force Then transfers to your leader and then line and then reel.
Your reel is the strongest link in your setup and I think you just turned up the drag too high hence the user fault.
As I said your rod should be the strongest , then your line Then Leader then your reel, but your rod is only 0.1KG stronger than your line.
Even if your line was a few KG under the power of your rod, there is stall a chance of breaking your rod if your not careful.
Just because you put a 11KG leader on does not make you rig into an 11KG setup, your rig will only be as strong as your weakest component which in this case 5.4KG your line.
Rods are always the strongest component even irl but not by just 0.1KG normally quite a few KG in difference.
ever wondered how people get for example land a 20LB fish in on a 7LB reel and 6LB line its because of 2 factors 1. The rod is the strongest component by a few LB's at the very least and 2. they have enough line to play that fish to tire it out and always fine tuning the Friction Brake but not too much to put to much pressure on the rod as this is the thing taking all the power.
Even with your rod being the strongest by only a few LB there is a good chance of snapping it if your not careful.
The more you keep your rod bend the more pressure it takes, which is why you never see people pointing the rod at the fish when reeling in and letting the line and reel take all that power