From your first link, with emphasis addd:
Five years and at least $600,000 on, with unhappy staff complaining of interoperability problems with Microsoft Office documents, city administrators called in a consultant from a Microsoft partner to support the city council in fixing the problem. The solution proposed: a complete reversal of course, switching back to Microsoft Office for a sum of at least $500,000, with a $360-per-seat cost for licensing Microsoft Office and no firm estimates for undoing the earlier migration.
There are no details on what the "interoperability" problems were. Was it features lacking in LibreOffice? Was it bugs in LibreOffice? The article doesn't say.
If businesses actually pooled their resources they could actually get LibreOffice "fixed" -- but they would rather piss money away on licensing costs.