You have a l2tp + load-balancing configured, this is a known 1.9.0 issue that has been discussed here -> https://community.ubnt.com/t5/EdgeMAX/Update-to-1-9-broke-my-l2tp-ipsec/m-p/1659615#M125299
This issue has been fixed in latest 1.9.1beta1 here -> https://community.ubnt.com/t5/EdgeMAX-Beta/Previous-beta-releases/m-p/1755479#M18802
Instructions how to access beta portal here -> https://help.ubnt.com/hc/en-us/articles/204908664-How-To-Signup-for-Beta-Access