(SOLVED) Issues with opening PDFs in Browser Read Mode

Hello everyone! I am having an issue with getting my PDFs to ALWAYS open to read mode while in a browser.

So I open the first PDF via a web URL and the PDF displays properly in read mode in my browser. Then I click on a link in that original PDF to navigate to another secondary PDF (via a web URL), and again it displays properly in the same window. However, after I click a link to go back to the first document (NOT the browser's back button), it now opens in regular mode, which shows the right side tools pane. I want it to always open into reading mode!

I am baffled by this...the first time I view the PDF it works fine, but then when I go back to any of the previously viewed PDFs in the same browser window, they open with the tools pane!

For more background, I have a one page PDF index with several links to other PDF files, accessed through a website link (they are all hosted on the same server). On those child PDFs, there are buttons to take you back to the parent. Anytime I view (through the same browser window) one of the same PDFs, that's when they exit from reading view into standard.

I hope I explained this well enough, but please let me know if I can further clarify.