ActiveConsole keeps flat file locked after "Fetch Next Line from Flat File"

We have a simple ube process that makes use of flat file (*.txt).

We receive a *.txt into an "Input Folder" from a 3rd party and need to process it.

For this we use the bsfn Fetch Next Line from Flat File

After processing all lines in the flat file (usually 1) we want then to copy the file to a "Processed Folder" and delete the file in the "Input Folder".

The code is straightforward, delete any existing copies in processed folder, copy input to processed, and finally delete input.

My problem is that the delete does not work.

I make use of B4700230 for all 3 operations but only the delete fails. No error message though.