I'm facing a perplexing issue with making my changes from a master page reflect on the front-end.
Strangely, if I enable my new master page on System Master Page it works, however when I enable it on Site Master Page changes only appear on the SP 404 page, not any other pages. Clearly, I'm missing something.
I am Using SharePoint Designer 2013. Also, I have Checked In and Published the changes.
I have read through most other duplicates relating to this question and I have tried all proposed answers and am now seeking further guidance.
My SP site is a Publishing Site, with a Welcome Page set.