The Client and Services build can differ and still work as expected. It is best to keep them within the same minor build branch.
For example 188.8.131.524 for the client and 184.108.40.2061 are fine but 220.127.116.114 and 18.104.22.1682 may not be. 6.4.1.x should be upgraded to a build within the 6.4.2.x range.
If you are in doubt on this, please contact support to verify that it is ok.