I feel I am in a bit similar situation as you are. Especially after a while, there will be so many ways to express the same thing as in the example sentence, it is almost impossible to guess the right thing without the hints, unless you learn the exact sentence with the exact missing part. And just to clarify, that is not what Bunpro is for.
What I try to do is actually understand the meaning of the grammar point, so I can use it myself, not learning the bunpro example sentences by heart, because that is useless. For this, I mean being able to use the grammar point: try writing out your own sentences or use it in speaking or even identifying it in Japanese texts or spoken language.
What I do know, is identifying grammar points in Japanese texts and actually making the point to remember and understand why that grammar is used in that sentence.
For me, Bunpro is not effective for learning grammar because it provides so little context, even with the example sentences, that I simply cannot learn it from Bunpro alone. I use Bunpro to review grammar, not to learn it from scratch. From my daily learning time, I try to keep bunpro maximum around 20% of it, but even that is too much I think considering my level.
Depending on where you are on your Japanese language journey consider pairing your grammar learning with active practice. As a beginner, I always actively practice conjugating the basic grammar rules, not just looking at them. At around the intermediate level, I usually buy a grammar practice books and review all the grammar points and do all the practice tasks. Beyond intermediate level, I learn the most by using the language.
It may be worth to research a little bit for yourself, what may be the best learning methods for your specific language goals.
Just put the full hints on.
Resetting your progress every time because of frustration leads you to re-do the same things again and again, which is a waste of time and energy.
And to be clear: just because you mess up a review for a specific grammar point, it does not mean you do not know it. If you can use it without problem, you know it. That’s it.