I'm sure there are other causes. Sorry to hear about the Addisons. I know it can be a challenging way to live.

TBH, I'd be tempted to ask my doc to tweak my dosage.

If you still have your adrenal gland, could you be still firing off small amounts of cortisone at inappropriate times of the day? I had the thing where I wasn't making enough cortisol in the early afternoon but making too much at night so had anxiety and insomnia (this was along with Graves' disease before I had my thyroid out.) I'm much better now.