計劃好的回國探望母親,看來是泡湯了!
It is possible that your case may still be approved in September, unless the officer on your case IS THE SAME officer your lawyer has connection with and knows he has stop the adjudication. Other officers are still approving I-485 cases for certain.
Even if you don't get approval in time. You can still travel using AP, and can change job at will because of I-485 pending over 180 days.