On the servers - modify file explorer to show hidden and system files - the look at the M:\ drive. You will now see the recycle bin for that drive.
I am assuming the value you are getting is from the column 'io_completion_request_address'. I would not expect to see an ndf file in the recycle bin - but if the application is creating a secondary data file and then deleting it - that file would show up in the recycle bin.
I would review with the application team to find out what they are running that would cause a secondary data file to be removed.