現在遞485，之後用H1換工作，180天後接上

According to AC21 2006 most recent memo, the focus of AC21 is that after having been pending for more than 180 days, I485 can be transferred as long as the underlying I140 is not revoked within the first 180 485 pending days. It has nothing to do whatever the status such as working or not working etc is in the first 180 days.

Even before AC21 2006 memo, there had been cases that got approved in such a scenario.

Your lawyer is right.

google it to find real cases.