Header going to change automatically

Hi there,

I have been experiencing an issue with the website header. I have built a custom header with tagDiv Builder and it has been working perfectly but sometimes noticing the header has been changing automatically to the default header.

How can I prevent it from changing the header?

Note:
Here is the website link: https://blog.interscale.com.au/
Here is the default header: https://postimg.cc/7JgSjRQZ

Thank you