Pixco 0,72x speedbooster

I have just purchased a focal reducer / speedbooster here : https://roxsenglobal.myshopify.com/products/fdr-nex-ma?_pos=1&_sid=e2094487d&_ss=r

Beware : not every A mount lens fits. When I mount a sony 50 mm F/1.4, the focus ring retracts the whole inner lens until it hits the adapter lens. The lens works fine, including infinity focus. But, I estimate the distance from lens'flange to outer-lens collar at 5,35mm. Others lenses constantly protrude more, such as the sony dt 1.8/50 SAM (6,5mm). They can't be mounted.