It may be on a steady decline. It's not looking like an isolated condition. There might be nothing you can do to prevent that decline. Just curious, because I do this sometimes, on an out-of-the-way branch, is the bud still green like there’s a leaf pending? Or are the buds dried up brown?
I had an oak dug up that looked just fine. However, once summer was in full swing, and the oak probably used up any stored reserve growth energy, the oak declined overall. I gave up when that happened.…so did the oak tree. Eventually it just moved to the burn pile and I looked for a new tree. Oaks, to me and my experience, are very tough to successfully dig up.
However, hang in there and hope for a redistribution of growth energy. It could happen. It might not happen. It would be nice to happen but don’t get too attached.