Vb6.0 project is not responding

When I run the exe file, sometimes it is running and sometimes responds with a delay, not immediately.
When I run it by F5, I have to try it many times to make it run and most of the times it is running with delays.
When it is not running, I have to end it using the task manager, which sometimes responds with a delay, not immediately.
The project was working before but when I added code for creating an xml file and sending it to an API server, then it started creating problems.
I am using vb6.0 under Windows 10
Any ideas to solve this problem?

I don't know many people here with a working crystal ball and I loaned my crystal ball out to a friend. This friend of mine hasn't brought it back yet! Don't you hate it when friends borrow things and don't return it ;)

So for the time being, we going to have to settle for being told what the first thing your program does is. What is it doing in Form_Load or Sub Main(). Most slow start problems occur there.

Sounds like you have some sort of long running blocking code in there at start up. A loop would be the first guess but need to see some code to really have much of an idea.

My guess is that HTTP requests are being made synchronously.