Unfortunately, OP, I'm guessing the pattern of trips with your parents, over an extended period, has finally triggered border interest. While you maintain that you've done nothing wrong, I would beg to differ. You admitted to working remotely while in the US. As others have said, I'm surprised they didn't turn you back around and void your visa. In terms of them interviewing you without your parents, while that might not be the norm in your country, in America, once you turn 18 (female or male), you are an adult and will be treated as such. If that is unsettling to you, perhaps visiting the US is not for you. My advice is to abide by the date given, leave before that date, tell your employer in Dubai that you are on vacation for the next four weeks (i.e. abide by the terms of your visa), and be thankful the border folk didn't revoke your visa.
As for your parents, they are also now on the radar. I would advise them to move sooner rather than later. It doesn't take YEARS to wrap up a business. They are using the GC as a tourist visa themselves, and trying the old trick of 'visiting every so often' thinking their status is good. It may not be and they might find themselves in a tricky spot in the future.
Overall, it's important that you and them understand the terms and conditions of yours and theirs' visas / status. It seems like you guys are skirting around the boundaries of those terms and conditions and, indeed, even breaking a couple of them. If being in the US is important to you all, please refamiliarize yourselves so you don't have a repeat.