Hello,

Please make sure that you made the header default on from WoodMart >> Header Builder >> Click the star icon to make a header default.

Screenshot for Clarification: https://ibb.co/PW1j7SX

Then you need to Go to Theme Settings >> Product Page >> Single Product header. And make sure not any other header selected.

Screenshot for Clarification: https://ibb.co/NnPRYYb

Regards.
Xtemos Studios