First, from the perspective of scientific psychology, it is your subconscious mind at work. Maybe you had some relationship with him before his death (that includes many implications, so I won't expand it in detail, so you need to remember for yourself whether there is something buried deep in your heart that has not been solved or realized), because dreams are a way of being expressed by the repressed subconscious mind in a changing form, which requires you to remember carefully. There are some things I don't want to think about when I'm awake. It may also be a subconscious nostalgia.
Second, superstition, old people generally have this experience, dreaming of their former relatives or friends. It is he who asks you for help and thinks that he trusts you and needs your help. Maybe it's their home, maybe something happened to his grave, and so on. This needs your attention.
Personally, I don't think it should be too serious. If it doesn't affect normal life, let it be. Maybe it's natural.