Level 2

QB2012 Desktop Mac does not update a file that was opened from a mounted partition.

When company file is on a mounted partition, the file opens, updates are in memory  but updates are not committed to disc and on close the backup file is written as configured to a non mounted partition (desktop), but the contents of the backup are equal to the file when initially opened.  (Mac OS is Mojave 10.14.2)  I've just switched from QB2009 to QB2012; I did not have this issue with QB2009.  Is   this unique to QB2012 Mac desktop?