I have two Tapo L530 smart bulbs, I configured them through the app. Things were ok. I had to travel abroad and my internet connection was lost from my ISP and reconnected the next day. After that, I'm not able to track the bulbs remotely. 

What could be the reason? The app says the devices are offline, but I have CCTV (different vendor - HikVision) with the same WiFi network and they are alive, only the smart bulbs are offline according to the app.

Could anyone please let me know because I'm abroad and no longer able to switch on the lights?