I have never, ever said that the delay could in any way reduce the amount of data available. Quite to the contrary, I have repeatedly said that the amount of data can only increase during the (completely unnecessary) delay.
You are the only one posting stuff like "If the while test found that there was serial data available, how can the delay make it go away?" Where did you get the idea that the delay would make the data go away? I don't think anybody except you has ever posted any reference to the delay making data go away. Perhaps there is a connection with lunar eclipse. How about it science?
This really will be the last thing I post on this topic. You have (more than once) posted code that contains: if(Serial.available() > 0)
The question that I have asked more than once, and that you have not answered, is what is the purpose of the highlighted statement?
The only reason it is included in the code is the fact that the code works with it included. I really know very little about C coding (only what I see posted in this forum and the arduino help pages), so I have to find code that works and modify it for my needs. I use a lot of code that has components that I can't explain why it is there other than the code won't work without it. If the "if" is not needed, then appropriately modify the code and then post it up, and if it works the same without the "iF", I will modify my test code. Otherwise, "This really will be the last thing I post on this topic." is appropriate.