(Accessibility) – Back button placement on the page in SPA

I am working with an SPA with Angular and the designs indicates that there is a back button and it is before the Page level heading usually the H1. For SPA, it is a general practice that we place the initial focus on load on the H1 heading, since only the main page contents reload.

From an Accessibility perspective, I feel that placing the Back button before the heading violates 2.4.3 - Focus Order as there is an interactive element that may be missed after initial focus in the page. Do you think it is an Accessibility violation if there is a back button placed before the heading in the DOM order. Thoughts?