Hello,
On SRX series, the only supported IPSec RA client is Pulse Secure though You may get other clients working without XAUTH.
As for Your exact release, in 12.1X47-D30 the Dynamic VPN (server side for Pulse Secure) is broken, see
https://prsearch.juniper.net/InfoCenter/index?page=prcontent&id=PR1135780 (Juniper login required)
With Pulse Secure please use JUNOS 12.1X46-D35 which is free from this issue.
HTH
Thx
Alex