GPIO0 will always oscillate for around 100ms then stabilise in the HIGH state, as described here…
If that 0.1 second oscillation is not causing an issue with your non-Blynk sketch then there are things you can do to make your Blynk sketch act in a similar way.
I asked you a series of questions, which you answered with very short replied. My response was to point you towards a so,utiin, and you then dumped some code in your next post, without any narrative about whether this was your original sketch (unlikely from your responses) or an updated sketch which still exhibited issues.
You’ve not responded to my request for more informative posts from you, so if you don’t want to share more information then you’ll need to figure-out the solution for yourself.
Pete.