I just got off the phone with TD ameritrade and the agent told me that the conversion of the shares to the new ticker symbol is via the company's agreement. In other words, the company decides when you will have it in your account. I remember reading that sharp wanted to avoid shorts manipulating the stock. So this must be what it means. I guess once humble decides we will have our shares converted in our accounts.
I have TD Ameritrade and in the same boat in a way. I’m not really worried about it though because i’m selling. I know what I had, I understand the split, and I can still track the price of the share and know my balance. At least the stock went in a positive direction today. Now if you were planning on bailing or selling I see you may have a problem. Once the ticker is updated your account will be as good as it was yesterday but with a quarter of the shares you which are current $4.82.