When importing multiple files with different sample rate than the one set in the project, no resampling dialog occurs even if “Convert to Project Settings and Copy to Project Folder If Needed” is selected. Audio files are imported into the pool at the original sampling rate and no resampling occurs. The only solution is to import audio files one by one.
This is an known issue. Already reported to Stienberg and multiple times mentioned here on the forum.
Thanks for the clarification