You may be having problems due to the disparity between difficulty and the current network hash rate.

Blocks are sometimes taking the entire network hours to solve and as a result the client believes it is not synced.

Keep the daemon-client running until the next block is solved and it will sync.

If you shutdown the client-daemon and the latest block it can get from the network is hours old when starting it again, it will again need to wait until current block is solved to sync up.