I checked your site and the menu uses Arial according to your settings https://prnt.sc/25326lm
So, make sure that you cleared browser cache https://chrome.google.com/webstore/detail/clear-cache/cppjkneekbjaeellbfkmgnhonkkjfpdn
What style changes did you make for the buttons? Could you, please, provide us with WP Dashboard access and provide screenshot of the buttons that did not change styles?
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.