Dell S2721DGF Vesa issue

[cakelover]

Hi wondered if anyone might have any suggestions my monitor arrived but wont fit onto my monitor arm. the vesa mount is deep into the back of the monitor so i can slide the monitor onto the arm do i need a new arm? https://www.amazon.co.uk/gp/product/B0757KX24T/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1