If your panels are showing as offline on the app you will need to contact your installer for support as Levelise are not panel specialists.
However, there are a few things you can check before you give them a call:
o The current generation Duracell system does not register PV power below 150W. Anything under this will show as 0W.
o The PV current clamp could have been moved or unplugged.
o The PV inverter could have tripped or may have a fault.
Have you had any other electrical work done in the house which has touched the system or the area around it?
For technical support regarding your Levelise hub please contact support@levelise.com