Your logo size is 250×100 and full size logo shown before this we think that you create a large size logo and due to css size resize but now we check it it’s size is already small.
if you want to increase logo size on sticky then menu height will be large and it looks bad.
Your logo looks perfect on all screen sizes then why you want to increase logo size?
Can you edit the CSS the admin login
Please see Details Below:
Admin Login: www.namalcogroup.com/wp-admin/
We can set height and width of logo through css in file style.css. If you delete the css the full size logo display.If you know the css then do this other wise your site admin info with us we make these changes for you.
How can the logo be edited to show actual size and not cropped?