I had problems syncing my Nano wallets a few weeks ago. Ultimately the problem was outdated drivers - go to your device manager (Windows) and update the drivers for your Human Interface Devices.
Thats not a 'syncing' issue. And it is also in no way related to ledger's API.
Your problem was completely client-sided.
While on the other hand the problem of the OP seems to be on ledgers end. The error message named "synchronization error" describes an error where the application can not retrieve all the necessary data from ledgers API server (e.g. transactions, current balances, .. ).
