Convert to Edit-Friendly only the first file works

What is your operating system?

What is your Shotcut version (see Help > About Shotcut)?

Can you repeat the problem? If so, what are the steps?
Very easy to reproduce.
Have two video files, that trigger Shotcut’s prompt to convert them to Edit-Friendly format.
Drag one of them to the timeline, notice the convert prompt.
Now, File-Close->No to start a new project
Drag one of the files to the timeline, notice the prompt, agree. However, if you now drag the second file, the prompt will not appear, even though the file needs to be converted.

Thank you for your report. This is fixed for the next release.