For security reasons Diffie Hellman (DH) key exchange is disabled on my system. The dropbox client keeps the status 'Syncing...". When I turn on DH and restart the client, the client starts syncing en keep my files up to date.
Can you update the client without a dependency on DH? There are supported alternatives. DH has been disabled since the publication of the logjam (https/weakdh.org/) attack in 2015. The client stopped syncing a few weeks back.