How do I clean the Ultra Retina XDR display screen of the new iPad Pro?

I’m using the new iPad Pro 11” 5th generation for graphic art. I have owned it for a few weeks and noticed that my finger prints aren’t being removed with a typical cleaning with 70% isopropyl alcohol. The screen has a fingerprint-resistant oleophobic coating, fully laminated anti reflective coating, and nano-texture display glass on my 2 TB model. I have used isopropyl alcohol since researching what to clean the screen with my past iPad pros and the alcohol has worked perfectly (as recommended by Apple). However, with this new iPad Pro my fingerprints and a tiny drop of milk seem to be permanently etched onto the screen even after cleaning. Should I be cleaning the screen with something else in order to protect all the technical stuff built into it? So far it’s 50/50 if you should put a protective sheet on the glass, but I prefer not to. And painting and drawing on this new type screen is heavenly. I can see a wavy type of pattern on the glass, which reflects light differently than my last iPads. I would like to hear from someone who knows something about this new screen. Thanks a bunch.