how to get passive +10 bug/glitch?

NOTE: My English for writing is not very good, for this reason I will be using a translator to do it, basically this is a copy of my "guide" in Spanish.

While reading the game tutorials and looking at the different options they gave, I discovered by accident this "error" which allows me to get the maximum limit of increases for the passive and give all my characters a nice and impure +10 to the bonuses of the weapon.
Warning, I do not take more than 5 hours of game, this is not if it is on purpose or a failure, not even look for the networks, simply "touching the options" I realized that the maximum number of "uses" that could give this option increased as I changed the passive but let's go straight to the explanation.

Let's take a step-by-step look at the problem.

I will leave a video (without voice) where I do it.

1- go to the "weapon" tab and select "fuse weapon".

2- choose the character you want to give an increase and then the weapon with the slots unlocked, can be one, two or thirty, does not influence anything. (I decided to choose a weapon from a slot in my video because I can show it faster).

3- from this moment the "failure" occurs, we choose a skill that we can take it to +2,+3,+4, etc, can not be +1, we will choose as an example the passive "Courage" and in our pull we have a total of 20, this ability to take it to +1 requests 10 and for +2 requests 5 then we need a total of 15 for the +2 we want to achieve, we put it to the weapon and without leaving or confirming, we go to another skill, we are going to do the same thing and we choose "Diligence" which also we have a pull of 20, taking it to +1 requests 10 and +2 requests 5, we put it to the weapon and then we are going to see that the pull of the first (that in this case was courage) increase a certain amount which rises every time we do this "trick", we do the same procedure as if it were a roulette without end until we get a nice +10, we give it to confirm and we already have our weapon with a passive to the limit.
One little thing about this point to keep in mind, always leave MORE points in your pull to be able to do this again, that is, don't spend all the value of skill +10 on a weapon because you won't be able to "increase" its quantity.

4- FINAL EXPLANATION OF THE VIDEO.
you are going to notice that many times I grab skills that can't be increased as "judgment" and that's why I explained above, not being able to give a +2 to the weapon, it doesn't increase.
I've already tried this method a little so I have enough points of the skills but it's just about that, take it to the maximum and change skill, even if you get to +10 you can still do the procedure to get more and more points, I do not know which will be your limit.

EDIT

I'm going to put a second video where I increase the limit of diligence and harmony, notice that I take it to +2 and change of ability to increase the "limit" of these and I ONLY confirm when I have a good amount of these and be able to put them in other weapons.
You can confirm when you have a +5 or +10, no problem with that, just check that you have a large number of these skills and be able to put them in other weapons :)

[エメベアー]

I wonder if this bug has been fixed in the latest update? Not sure if I understood it right, since it doesn't seem complicated, but it's not working for me

[Rig]

I'll need to re-read it to understand better what happened (my brain is already tired lol), but i'll give it a try. Thanks :D

[AOB 606]

This is acutally useful with rare elements thank you .