Acrobat Pro DC colour anomalies

Has anyone else experienced inconsistencies with CMYK colours since the recent Acrobat Pro DC update (Build: 19.8.20071.303822)?

We're finding that most of our print documents (pdf X-1a), whether created with InDesign or Illustrator, are now showing colour values in the pdf files (created directly from those programs) that differ from the original values, usually by just 1%, in the cyan, magenta and yellow channels. Black seems to be unchanged.

Pdf documents created prior to the latest update to Acrobat, whose colour values when viewed in Acrobat matched the colours from their origin documents (InDesign or Illustrator) also show this 1% discrepancy in the new version of Acrobat.

It's only a small difference, but it's still disconcerting when trying to assure clients that their corporate colours will be printed accurately.