When you open o365 Account page in the collection property and don't change anything just click OK, the password in DB will be replaced with '********'
Known defect - MMEX-3916.
This is a known defect - MMEX-3916. A 8.14 fix is scheduled for the end of January 2018. No code fixes will be provided for earlier versions.
Do not click OK on the tab "Configure Office 365 Settings", if nothing was changed within the settings.