Emil, you have to make sure if AP is crossing L3 boundaries then you need to fix the ZD IP in AP via CLI using below command so AP will find the ZD for sure.
set director ip primaryip secondaryip
Example: set director ip 0.0.0.0
take a look at this KB article - https://support.ruckuswireless.com/an...
for more info
About ports: you need to have LWAPP UDP ports open on your firewall/router.
Also ensure that latency of your VPN is less than 100ms.