Hi,
If you are wanting to control all 8 relays independently then the ESP8266 will be a problem because it doesn’t really have enough suitable GPIO pins.
See this for more info:
An ESP32 would be a better choice.
Without seeing your code, it’s difficult to know how you’re trying to achieve the timing, but my guess is that you’re using delay() which isn’t compatible with Blynk as it blocks all other code execution and will lead to Blynk disconnections.
You should search the forum for examples of how to use timeout timers.
Pete.