I just saw your other post about how to get your bunny to eat hay. You said you’re buying Oxbow and may try some Kaytee. This may be the problem. Sometimes bags of hay in stores sit there for a long time — sometimes in the store, sometimes in the store’s warehouses.
To really see what hay your bunny likes, try to get fresh hay — local farms (must be horse quality hay), online distributors (KMS Hayloft, American Pet Diner, Small Pet Select, etc). Try different cuttings as well — 1st cutting is stalky and crunchy with leaf, 2nd cutting has thinner stalks than 1st but much more leaf, 3rd cutting is all leaf on timothy. Orchard 1st cutting has stalk but mostly leaf, and 2nd cutting orchard is all leaf. Oat hay is mostly crunchy stalk and seedhead (the seed heads are super tasty to bunnies but high calorie). Living in the west coast, you are in the best place to get great hay at the best prices from online distributors.
1st cutting timothy is in harvest right now,2nd cutting should be available starting in a few weeks (dependingbon where you get it), and 3rd cutting will harvest in late September into October.