All my 8 device are unable to connect to blynk.cloud, happen to day.
I have also changed internet provider, so I am not sure if this happens before or after i switched connection.
Any Idea
When you switched ISP did you get a new router?
Did your WIFI SSID change?
If you kept the same SSID but your hardware changed did you ensure that you have a 2.4GHz network with the correct SSID for your devices to use?