Conflict with Ultimate Member, TagDiv Cloud Library Headers and PHP 8.0

Hi,
My site is at https://www.pnwbeyond.com —
I am scaling back a bit, and was doing some maintenance and finally upgrade to PHP 8.0 after it seemed all plugins were compatible — only to have a critical error.
This error only occurs when I have PHP 8.0 enabled and am using a Cloud Library header template and have Ultimate Member enabled. It does not occur with Ultimate Member and any other theme, but it occurs when I use the base theme (not my child theme). If I try to create a new Cloud Library header template, it’s blank and nothing is imported.

The error does not occur if I set the header to “No Header”– then it just shows a plain default header.

I don’t want to use the Standard Pack but reinstalled it to see what would happen. Using a standard pack default header, it works fine.

If I look at my error log I see:

[Got error ‘PHP message: PHP Fatal error: Uncaught Error: Attempt to modify property “classes” on null in (I excluded some stuff here)/wp-content/plugins/td-cloud-library/shortcodes/header/tdb_header_menu.php(1270): tdb_header_menu->inner()\n#5 …/wp-content/plugins/td-composer/legacy/common/wp_booster/td_glob…’

How can I fix this? I want to keep PHP enabled and I want to be able to re-delete the standard pack and use a cloud library header again. I don’t want to mess with some other membership plugin — I just need it there to keep people submitting events from accessing the back end of the website.

Thanks
Cheryl