The RS Throughline, like all the other throughlines, needs conflict. No conflict, no story ! The "Problem" element is a form of inequity : how it plays out in the relationship, be it positively (a motivation that keeps the bond alive) or negatively (a problem that drives them apart), is up to you ; but it will create conflict because it is that - an inequity. Only by employing the Solution element will the conflict come to an end. This "Solution" element can be seen as a demotivator for a more positive relationship, or a solution in a negative one : either way, it rights the inequity. Is it a good thing, or a bad thing ? It's up to you.
I don't have examples for Good/Negative RS or Bad/Positive RS but it's entierely to create that. But really, it's not a matter of Storyforming, it's more a matter of Storytelling. "Positive" or "Negative" are storytelling tools because it is a subjective view of your story as seen by the characters, whereas Dramatica gives you an objective view of the Relationship and what is needed to right the inequity at its core.
If the Solution element is never employed, the throughline ends in Failure. However it doesn't mean it has to be portrayed in a negative light. It's like a Good/Failure story. Take How To Train Your Dragon : in the OS Throughline the solution is never employed, ergo failure, but it isn't portrayed as a bad thing - everyone's happily ridding dragons at the end so although it's not a triumphant ending, it definitely doesn't "feel" negative. If the writers wanted it, they could have emphasized the failure on the part of those who were for the Story Goal (making them lament their loss, showing more profound consequences, etc.), thus creating a really bittersweet feeling. The same thing can apply to the Relationship Throughline. Objectively, the goal is to solve the inequity. How you choose to portray that is a matter of storytelling, so it's all up to you
But otherwise it is entierly possible to have a RS Throughline that ends in "failure" and still have a judgment of Good, and vice-verse.