Many other reviewers for similar products on other pages have also stated this same problem:
This adapter is very tempremental. The design of the inside springs to hold the pins of the shaver in place is too strong. They push the pins of the shaver to the side and break the contact, so that unless you are physically holding them in place (or wedge them against something) no power gets to the shaver, as there is no contact between the pins on the shaver and the contacts inside the plug. Extremely cheap and bad design. I realise the product is only £1/£2, but this defect renders it practically useless.
To be avoided.