Airport Express drops signal...why?

Here is the pitch. I have a friend wiht an AEBS and three airport expresses; basement, family, kitchen.

From a distance point the family room is furthest from the AEBS while kitchen is about midway in terms of distance.

Kitchen frequently is going offline. Others are fine.

New home with brick construction. Kitchen is plugged in to wall adjacent to sink and away from microwave and other appliances. Socket has a wood cabinet overhead.

Wondering if there are any best practices for locating these devices. I'm thinking the cabinet might be interfering but cannot understand why.