Today I had a stop order in for some SPY puts around noon. Market went my way so I decided to sell, went to the order type tab, left clicked it, noticed it only gave stop or market order, so I canceled it then made a new sell order. 3 hours later a box suddenly pops up telling me I can't sell naked puts. I am confused and X it out. About 5 minutes later I realize it was the stop order triggering. I have had multiple instances where I went to create and order and when changing the default order size to the size I want, it changes back to the default size as soon as I click to change the limit price. As expected, IB was a bit uncooperative. I assume this is my fault since I have only been trading with real money for about a year but maybe I can find some false sense of comfort if this has happened to someone else.
I'm not really sure about the details, I would ask but since I don't care I would say there's a few things you should think about. One, if you had a sell stop to enter the position, then if price moved through quickly your order may not have been filled. Especially with options this can happen. In the future, always check your portfolio tab so that you know exactly what your holding, and always make sure all orders are cancelled once you finish your trade. It's easy to leave a stop on there that you've forgotten about. You may just want to use the book trader, it's easier. After you're done, just click cancel all trades like 4 times to make sure you clear it up.