Otter,
It could be you're still recovering. I'm over five years from surgery and still have ups and downs. I'm a professor at a university with a PT program and I was a special guest last fall in a class specifically on vestibular PT. They did all sorts of tests on me. I think generally my balance is very good and no one would notice my issues. But, the professor of this course told me she thought I could still improve my balance even further if I kept doing certain exercises. So, I guess my point is that at this point, it may be less about "recovery" than just overall need to engage and improve vestibular performance.
We just came back from vacation in Banff, Canada. When we visited the glacier at the Columbia ice field it was about40 degrees (F), raining, and super strong wind. In these conditions my balance really suffers. I had to hold my son's hand to get back to the car! Worst episode I've had. Once I warmed up I was fine.
good luck!