Shared library syncing problems Endnote X8.2

We are a group of reviewers at a UK university using an EN library with 1200 records in it for a systematic review project.  The records have been added to groups (Not smart groups) in EN and we are going through each group adding $$ tagged keywords to the Keywords field, that are relevant to the project.

This issue is as follows:

One member of the team can be working on a PC in the office or at home and tags all of the records in a group.  This person then ‘syncs’ up the EN library to the cloud.  However, when this team member tries to sync down the library to another PC, or another team member tries to sync down the library, not all of the tags are there.

Some further information:

I am working at home and have just been looking at the activity feed tab on the top toolbar in EN.

When I scroll down to activity on Wednesday last week, when I was working in the office, its says that I modified 202 references.  However, when I click on this only 121 go into search results.  

It seems as if EN has recognised that I made 202 amendments at work, but is unable to identify amendments for 81 records on my home PC.