IPSec Site to Site not working properly between Peplink Balance 20 and Ubiquiti Edge Router PoE

Hello Guys. I have a little issue here. Hope you can help me out.
1- I have an IPSec Site to Site established between an Edge Router PoE and a Balance 20. This is working half way.

2- The issue is that I cannot access one of the networks on the Peplink side.

3- The network on the Edge Router is 192.168.50.0/24 and the networks on Peplink are 10.1.20.0/24 and 172.16.20.0/24. I can access the 10.1.20.0/24 network with no issues at all. However, I cannot access the 172.16.20.0/24 network.

4- The 172.16.20.0/24 is not actually a network. It is a static route on the Peplink router (IP 10.1.20.2) pointing to a Vlan on a switch (IP 10.1.20.1). The static route looks like this on the Peplink:
Destination Network Subnet Mask Default Gateway
172.16.20.0 255.255.255.0 10.1.20.1

I have attached a picture of the issue when going to IPSec VPN tab on Status Page.