I make a series of landing pages for clients, each of which has a custom header and footer with the company’s branding. It has become a challenge to make these header/footer assignments stick consistently. Is there a particular naming protocol that I should be following for headers and footers, because that seems to make a difference?
For example, say I have a client named SampleCU. If I name the header “header-SampleCU” it may work. Until it doesn’t anymore. But then if I add a digit such as “00-header-SampleCU,” the assignment may work again. But not in all cases. And for some other clients, the “header” prefix didn’t work at all, but if I used “head” or a different abbreviation, it then would work. And it seems to change with every theme update.
Clearly I’m doing something wrong. I’ve deactivated all plugins in a staging environment and the issue persists. Any help would be appreciated.

