I am sharing the answer from your duplicated support thread, for convenience and better visibility from the community:
The ClickToOpen is applied only to the opening of the root items. As you can see in the article, then collapse works normally, meaning the menu is closed when the mouse hovers out of the menu.
Nevertheless, you can use the approach of the following KB article, which will not close the menu item when the mouse hovers another root item:
Progress is here for your business, like always. Read more
about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.