Problems.
As a leader, it is concerning if team members do not approach you with their problems. There are two possible reasons for this:
People don't believe that you care about them.
People don't believe that you can do anything to help them.
In either case, you have lost your ability to act as their leader. So, what can you do to avoid this situation?
When someone brings up a problem, make sure to really listen to understand. Avoid applying your own mental framework to their problem too quickly and fail to see what they mean.
Summarize clearly who is going to do what. Be specific about what you plan to do about it and when/how the follow-up will happen.
When you find a solution to someone's problem, share it (within the limits of confidentiality) or ask the other person to share it. It is key for your team to see examples of what issues you can help with.
Most likely, you need to reach out to a wider internal network to find a solution to the problems raised in your team. This only works if you have managed that network of yours properly. So keep helping people widely, and you will always have help available when you need it.
On the opposite side, you don't want team members to use you as a dumping ground for all their issues, nor do you want to listen to endless rants about things that are beyond anyone's control. Instead, you want people in your team to exercise good judgment about what to bring to you and what not to. Achieving this balance can be tricky and may take some time for everyone to grasp. Your consistent coaching here is crucial. Here are some thoughts that could help:
There must be enough psychological safety in the team so that people can be open and direct with each other. This includes giving feedback to their peers directly instead of always coming to you behind their peer's back. There are exercises and activities that can accelerate the build-up of trust in the team.
Make it clear to everyone that your team is not a forum for dwelling on "gravity problems." You may even want to adopt a slightly humorous intervention when someone is taking too much airtime on a problem that is clearly beyond the control of your organization. You can call it "Gravity!" or something more funny or unique to bring the discussion back to things that are relevant.
Coach your team on the most productive way to raise problems. Before raising a problem with you, they should try to a) define the problem as clearly as possible, b) come up with their thoughts on potential solutions, and c) have a preferred solution or ask in mind to discuss with you.