Same issue here. Disable plugin, add new post screen works correctly. Activating the plugin breaks the jquery.
Uncaught ReferenceError: XyzFbapToggleRadio is not defined
at HTMLDocument.<anonymous> (post-new.php:1171)
at i (load-scripts.php?c=1&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable,jquery-ui-position,moxiejs,p&load[]=lupload&ver=4.9.5:2)
at Object.fireWith [as resolveWith] (load-scripts.php?c=1&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable,jquery-ui-position,moxiejs,p&load[]=lupload&ver=4.9.5:2)
at Function.ready (load-scripts.php?c=1&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable,jquery-ui-position,moxiejs,p&load[]=lupload&ver=4.9.5:2)
at HTMLDocument.K (load-scripts.php?c=1&load[]=jquery-core,jquery-migrate,utils,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable,jquery-ui-position,moxiejs,p&load[]=lupload&ver=4.9.5:2)
Not using any caching plugins, or cloudflare.