> which is returned to your account as cash which is being mistakenly calculated as additional buying power
Almost, but that's not exactly the issue. In fact, the issue is probably worse. If you write those calls, you definitely get actual, real cash for them. So that's not the problem. But if you wrote deep ITM calls (as is the case here), your stock on the other hand is virtually gone. So the issue is that they compute an incorrect value for the resulting portfolio (you can see it in the screenshot, where it says "$3,999.88 portfolio"; that is definitely wrong). The cash part is correct; to some extent the stock part is correct too, but if you add the outstanding calls in the mix, the portfolio value is in fact pretty much just the cash (plus a small premium).
