A quote from the signal vs noise blog. "Sometimes a design isn’t working because you think you can’t change the one element that needs to be changed"
The same goes for problem solutions. Maybe you're not finding an effective solution because you are locked in on something as being essential when it isn't. Take a step back, attack the problem with a beginner's mind and maybe another solution will present itself.
I was once faced with an analysis problem in which I couldn't avoid the compound I was trying to analyze decompose in the equipment. After many iterations of trying to find a way to avoid decomposition, I finally realized that if I deliberately decomposed the compound in a known manner, the solution was easy.