Cannot add product tab on live store

I have multiple product tabs with unique HTML blocks working fine in demo mode on my local server but, on the live store, all the tabs show the same content, e.g. if I change the content of one tab, the content of the others tabs of the product are changed.

Any suggestion very welcome!!!

Well… and the solution is… open the tab in a different browser, fill in the html code and close. Do not open another tab otherwise code will be replaced. Kind of weird.