When I’m called over to help out with a tricky problem in a complex software system, I’m typically hit with lots of detail on how the problem is manifesting. Typically my go-to response is “let’s take a step back”...
In a lot of instances, issues that manifest in a very specific way are in fact symptoms of a larger scale problem, so it’s important to put them in context. Pull back far enough, and the bigger problem should become apparent - staying micro-focussed can obscure the view.
It’s an unfortunate fact of Software Engineering that failure modes are typically the worst tested code paths, so a failure at one level will often manifest as a subsequent failure at another level. Make sure both (or all!) problems contributing are identified and fixed.
When problem solving, make sure you don’t miss the forest for the trees.