Zend certified PHP/Magento developer

Unable to Manage Options (Values of Your Attribute) in Product Attribute

I am baffled. I cannot add to, or reorder existing product attributes. (Note: This is a site I inherited, so I didn’t build it.).

I have max_input_vars set at 20000, up from 10000. Nothing I try works. It simply doesn’t save in the database, and I get no error messages.

Using Magento EE 2.3.4, but the issue is also on 2.3.1 as well.