The buckle is the point where something fastens and holds, read as commitment and security. A broken buckle is linked to a promise or arrangement that feels less firm than before.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.