HELP: H1B gap for university faculty

My 485 has been pending for more than a year. I decided to move from University A to University B this fall. My current H1B with A is about to expire in July. Even if it was renewed, the last day at A would be Aug 22. However my new employment at B won't start until Sept. 2. No matter I use H1B transfer or EAD, there is always this about 10 days gap. Can anyone help assess the impact and how to avoid it if possibly at all? I really appreciate it!!