Helix Ultimate 2.2.3 / SP PageBuilder 6.2.2 / Joomla 5.4.1

We performed an update from Joomla 4.x to Joomla 5.4.1. Everything ran without any error messages. However, in the new system, the “>” for submenus in the main menu and the off-canvas menu, including the links, have disappeared. They were replaced by the special character (square □) without links. What could be the reason for this?

We are using: PHP: 8.2