Double customer bar in checkout page

Have you checked whether your theme supplier has published a 2.5 compatible update.

Please post the url to your site.

https://apshop-serramenti-online.com/ap-shop-online/

I use avada theme
Thanks

I see it. I’d take that problem to the theme vendor’s support service.
https://themeforest.net/item/avada-responsive-multipurpose-theme/2833226/support

Meanwhile you can hide the second one with this custom css:

.avada_myaccount_user:nth-child(2) {display:none}