One dog settles with a chew. The other walks over, and the first goes still and growls. The growl is a warning that the situation is not comfortable. Don't punish it, reach between them, or leave them to "work out" ownership.
For now, give chews, food puzzles, and favorite toys in separate rooms behind secure doors or barriers. Pick up the items before bringing the dogs together again. Ordinary toys may be fine in shared space for some pairs, but watch for a dog standing over an item, blocking access, or following the other dog away. If a fight has happened, separate safely and seek veterinary and qualified, reward-based behavior help. Human hands near a fight can be bitten.
Make resources less of a contest
Provide each dog their own resting and feeding space, water access, and time with you. If one dog cannot relax when the other approaches, more toys on the floor may not solve the worry. Note which items and places cause tension and whether a health change has altered one dog's tolerance. Your veterinarian can check for pain and other contributing problems.
A professional may help with training at safe distances, but you do not have to make the dogs share a chew. Separate enrichment can remain the long-term routine. It is a practical way for both dogs to enjoy what they have without needing to guard it. The resource-guarding guide can help you understand why the toy matters, keep the dogs apart around valuable items while you seek an individual plan
Sources: Dogs Trust: Resource guarding in dogs. Dogs Trust: How to understand your dog's body language.