in a private project I use several slide menus and an IFrame, which displays content with HTML links.
The slide menus are very long, so they overlap the IFrame.

The problem is now that I can't click the links inside the IFrame if they are within the overlapping range of the slide menu. It also doesn't work when the slide menu is closed. If it is expanded, it is logical that it does not work, because then the content of the menu is clickable.
In the screenshot you can see the link Zur Navigation under the menu item 3SAT within the IFrame. This link is not clickable, even if the menu is closed.
I've already swapped the Z-order of the menu and the IFrame, but this only reverses the problem. Then there is nothing more selectable in the opened menu, which is in the overlapping range of the IFrame.
Optically everything looks perfect, but unfortunately the slide menu blocks all areas also in collapsed state, which it overlays in the opened state.
Is there any way to change the behavior?
Thank you very much.
Markus