I have the same problem with my light panels.
My Panels where offline today. Fighted one hour with multiple resets to connect again.
Updated the firmware to 3.1.5. App shows not connected but I can switch on the panels if I push the on button multiple times. App shows offline regardless.
Im speaking with Proffesor x ( Xavier) in here and he is on this case.
It use to work..you can try hard reset urs..dident work for me tho…take the power cable out of the wall and press both bottons on the panel while you plug it in again..might use 2 person if you cant reach :D then after a hard reset try and pair again