A family of Microsoft word processing software products for creating web, email, and print documents.
I'm glad you got it sorted.
Indeed, actually finding and selecting an object which is anchored to the header might be tricky at times.
The Selection Pane might help. To display it, go to the Home tab; in the Editing group, click Select, and then click Selection Pane.
You still have to activate the header/footer as discussed earlier.
In the example below, you will see the object name in the pane and you can click it to select the corresponding object which is anchored to the header.
Note the anchor in the header paragraph. To see it when the object is selected, click the ¶ icon on the Home tab.