My Primary Menue is set to “Fixed to Top on Scroll”.
The plugin “Easy Table of Contents” creates the table of content and uses/creates anchors in the line of headers (h2, h3).
Since there is no vertical offset for anchors the anchor position disappears behind the fixed Primary Menue. I handle manually set anchors by positioning them well above the line of interest. Nevertheless automatically set anchors will not work as to be expected.
I really don’t think there will be any way to fix this while using the fixed top menu.
The only thing I can think of is to move the anchor label to the front of the paragraph instead of the title. The names in the list are arbitrary, and don’t have to be the actual title in the content. But that might not be quite enough space.