I regularly see people asking about wallet not syncing. There may be multiple reasons (I can speak for Windows version).

1. Firewall blocks the port the wallet runs - Make sure you allow the port wallet uses in your firewall
2. Incorrect Clock time syncing - Make sure you enable "Set timezone automatically", Synchronize your internet time and use NIST's clock for syncing (they appear to be more accurate).
3. No connection with nodes - Add more nodes into signatum.conf file (you have to create the conf file)
4. AV or other similar software blocks - Ensure you download the wallet only from official link (that's a safe link) and add them to the exclusion list.
5. Poor network connection - check your internet connection
6. Give it some time - Once you add nodes or get some connections, it takes a lot of time to sync. Make sure you keep track of the current block your wallet has synced with, give it some time and check if it has increased.

PS: I'm using the old wallet and did not face issues with either versions.