I haven't noticed it myself. Cell phone still works inside my local home depot. Back in college the engineering building used metal plates as the outside faca

I haven't noticed it myself. Cell phone still works inside my local home depot. Back in college the engineering building used metal plates as the outside facade, combined with concrete construction. It had a side effect of getting rid of any cell phone reception as a result, unless you were beside a window. The building was built before 2G cell phone service was a thing, so it wasn't an intentional thing.