Diagnosis
The unit has power, but your home internet router probably came back online slower than the iSmartGate did. The iSmartGate got confused and didn't reconnect properly when the Wi-Fi network returned.
How to Fix It
Don't touch the app yet—it's looking at old, cached info. The fix is at the router. Unplug the power cord from your Wi-Fi router for 30 seconds. Plug it back in and wait for all its lights to settle into their normal pattern (this can take 2-3 minutes). Now, go to your iSmartGate Pro unit. Unplug its power adapter from the wall, wait 10 seconds, and plug it back in. Watch its light: it should go green, then red, then finally solid white as it boots up and finds the now-stable Wi-Fi network. After a minute, force-close and reopen your iSmartGate app. It should now show 'Connected'.
If That Didn't Work
Your router might have assigned the iSmartGate a new IP address after the outage that's causing a conflict. Log into your router's admin page (usually by typing 192.168.1.1 into a browser), find the list of connected devices, and see if the iSmartGate is listed. If it is, there's a 'Renew Lease' or 'Reconnect' option next to it. Use that.
Heads Up
For future outages, consider plugging your router and iSmartGate into a small battery backup (UPS). Even a cheap one will keep them running smoothly through brief blips and give them a clean shutdown if the power's out longer, preventing this reconnect headache.