It speaks to the state of Shipstation support when questions go months without an answer and the only response users get are from other users. Needless to say, Shipstation support is non-existent and, when they do randomly and infrequently help out, they don't know the answer to anything.
Well @peachyapricotde , since Shipstation support sucks, I can shed a little light. Our Shipsurance balance was added to our Stamps.com balance on 6/15. Conveniently, this was the same day that I reached out with anger over that Shipstation support is completely absent. It "mysteriously" appeared in our account on the day I reached out for help.
I recommend checking your Stamps.com transaction history, but it wouldn't surprise me if they're holding your Shipsurance money hostage and hoping you forget.