Nested shortcodes with Visual Composer

Hi,

After upgrading wordpress and my theme (that uses Visual Composer), this following example doesn’t work :

[su_accordion]
[su_spoiler title="1st level title" icon="arrow"][_su_spoiler title="2nd level title" icon="arrow"]The content for the spoiler[_/su_spoiler][/su_spoiler][su_spoiler title="2nd example of 1st level title" icon="arrow"]The content of the 2nd spoiler[/su_spoiler]
[/su_accordion]

The 2nd word of the title of the 2nd level is trimed.

The same code on another website and it works flawlessly.

Any help would be very appreciated ! Thank you !

https://www.ads-software.com/plugins/shortcodes-ultimate/