This is strange and I do not face such issue with chrome or FF browser.
1)
Could you please try to resolve your issue by deactivating all third-party plugins as well as the default theme to check for any possible conflicts with any of the plugins or themes?
2)
Could you please activate WP_DEBUG from wp-config.php file and send me possible errors for review. (errors found on your page or on your browser console)
i found that the issue was generated by the Page builder & Shortcodes - hidden link
used by my theme Barber Shop. Disabling the Page builder Toolset Access expand and collapse properly. Not very convenient for me discovering that my theme is incompatible ... i will think how to fix this ...
If you have any idea you are welcome
Best,
Federico
This ticket is now closed. If you're a WPML client and need related help, please open a new support ticket.