I have the same issue. I disabled all plugins. When AIOSEO is activated, console shows the error:
event.returnValue is deprecated. Please use the standard event.preventDefault() instead.
XHR finished loading: "https://website.com/wp-admin/admin-ajax.php". load-scripts.php?c=1&load%5B%5D=jquery-core,jquery-migrate,utils,jquery-ui-core,thickbox,underscore…:5
send load-scripts.php?c=1&load%5B%5D=jquery-core,jquery-migrate,utils,jquery-ui-core,thickbox,underscore…:5
x.extend.ajax load-scripts.php?c=1&load%5B%5D=jquery-core,jquery-migrate,utils,jquery-ui-core,thickbox,underscore…:5
e load-scripts.php?c=1&load%5B%5D=hoverIntent,common,admin-bar,schedule,wp-ajax-response,autosave,jqu…:74
(anonymous function) load-scripts.php?c=1&load%5B%5D=hoverIntent,common,admin-bar,schedule,wp-ajax-response,autosave,jqu…:74
This message continues to generate. De-activate and everything works as expected.