This is actually something I love doing with our junior developers: Often they have a question every once in a while, or they don't have any questions for too long so I ask them what they're doing currently. Both often leads to me taking a look, and discovering that they're like five miles deep into a dead end without realising it yet, and we spend an hour or two working on their problem together.
I love that time, since they usually start asking more and become increasingly confident calling my decisions into question, which in turn leads me to reflect on why I do things the way I do them, and we both end up smarter than we have been before.
One other thing I often notice is that when you're good at something, you don't care about looking good doing it. I have no qualms admitting I don't know something, or that I'd also start asking AI, or just throw some at the wall and see what sticks. This tends to build up a lot of trust with the juniors, since they realise I'm also just putting my trousers on one leg at a time.
Sure, it can be frustrating sometimes to wait for them to just… get the obvious right in front of them, but that usually comes very quickly. I can wholeheartedly recommend spending time with your juniors!