I agree with @skilesferne . My GSD went through something similar, and it turned out he had mild hip dysplasia. Fortunately, it didn’t require surgery, but the vet recommended joint supplements like glucosamine and chondroitin to support his joints. Also, regular light walks and avoiding sudden jumps can really help. If the issue persists, you might want to consult with an orthopedic vet who specializes in these types of problems. Joint health is crucial for this breed since they’re predisposed to these issues, but if caught early, it’s often manageable without major complications.