Do you already try to off and on the modem to refresh the connection before ?You also can try self troubleshooting via easy fix> https://easyfix.unifi.com.my.
If issue still the same, you may contact unifi contact center via channel below. They will assist you on the issue.
Live Chat - https://maya.unifi.com.my/
Email - email@example.com
Facebook - We are unifi
Twitter - @helpmeunifi
Have you try to turn off the Router and modem for 15 second and check again your connection?If it still same,you may report to LiveChat to make a further checking on your connection status