Fidelity had big problems yesterday. I was on the phone with them at 10am and problems just got worse throughout the day.
Early in the day, municipal bonds were having major issues. I placed an order to buy some bonds, cancelled about 15 minutes later and it remained as Pending Cancel...for an hour before I called. Another, which was Fill or Kill did not fill, and had not killed after an hour when I was calling. A third was a bond I submitted to sell, but it was not posting as in inventory to sell. This had happened to me in the past, they were not able to resolve, and things did not clear up until overnight. When I called, after being put on hold for 15 minutes, the rep came back and acknowledged that there were issues. She said they were working on it. Same ultimately happened this time - did not confirm cancellation until overnight.
Later in the day, the problems spread to submitting stock orders to buy shares in ATP platform. Upon submitting the order, it would come back with "account information is not available, call for assistance". I was able to work around it getting orders through via the website and other pathways through ATP.
My big problem when this happens with the municipal bonds is that while the orders are Pending Cancel, the funds remain committed to those open orders. From what I saw, as far as what the market was showing, the orders were in fact already cancelled, however, Fidelity was not acknowledging it, and so those funds remained unavailable for investment until early this morning.