That's exactly what I showed him (The head of Nonthaburi Immigration, but he answered that this police order isn't talking about an "affidavit" but about a proof of income, certified by the Embassy or Consult.
I just tried different browsers and they all work just fine (Chrome, Microsoft Edge, Opera and Firefox).
I think your problem is that you use a pop-up blocker or so and that your settings prevent the immigration site to open their pop-up window for showing the "to print' page.
No one asks for TM30 for your 90-days notice. My point is that they already know that information via the TM30 database. They didn't before. So that means follow ups and cross data between the different departments is improved these days.