Acrobat does not remember the correct last-viewed pages for PDFs at startup
Windows 10 64-bit, Adobe Acrobat Pro DC 2020.013.20064 (and Acrobat Pro DC 2019; same bug)
With multiple documents open in tabs, and the settings to ‘Restore last view’ and ‘Open PDFs from last session’, Acrobat is supposed to open the session exactly as it was closed, with the right last page for every document. Instead, on launch the pages for most documents are incorrect and only one document displays the correct page.
It saves this setting in HKCU\Software\Adobe\Adobe Acrobat\DC\RememberedViews\cNoCategoryFiles which has subkeys for every document, ranging from c1 to cN and their subkey cViewDef\ includes the important value ipageViewPageNum, also values such as ipageViewMaxVisPageNum and ipageViewMinVisPageNum.
The values should be set correctly and independently of other documents present in HKCU\Software\Adobe\Adobe Acrobat\DC\RememberedViews\cNoCategoryFiles
When closing Acrobat, the values ipageViewMaxVisPageNum and ipageViewMinVisPageNum are set to the correct page, but the value ipageViewPageNum is set wrong, which makes the wrong page display at startup. In fact, that value in question is set arbitrarily to the last actual document you chose to work with. Meaning, if you have 4 documents open, and read the first document only, all 4 will open up to the page of the first document, and each ipageViewPageNum will be identical copies of the value corresponding to that first document.