Hello, @Tuccios
Try to disable the Nice Scroll option. Please create a separate topic for questions – http://prntscr.com/pvs8cy https://www.8theme.com/forums/legenda-support-forum/ Describe your problem on the checkout page in more details. Try to disable all the third-party plugins, that do not come bundled with our theme https://www.8theme.com/demo/docs/legenda/Plugins/Included_Plugins , and check how it works then.
Regards
