Hello,
One of our clients told us they were facing the issues with softaculous when opening the software in a new tab so we have fixed it by executing the following commands and this fixed the issues with softaculous
chown root:root /usr/local/cpanel/whostmgr/docroot/cgi/softaculous/bin/soft
chmod 4555 /usr/local/cpanel/whostmgr/docroot/cgi/softaculous/bin/soft
Best Regards.