2FA app doesn't work sometimes

Unfortunently 2FA with MSP360 doesn't work sometimes. 1. The app does notification for the 2FA auth request when I am going to perform admin operation. 2. Tap "Confirm" of the auth request on the MSP360 app. 3. But the MSP360 Web console doesn't handle my approval from the app. I guess I face the situation from night time to morning time of JST mostly.