HotFolder Not Converting All jpg files

I have a hotfolder configured to autosave to its current location.
Profile is set as below.

Save
Automatic is Enabled
FileName =
Target Directory =
Dont overwrite existing files is enabled

Convert
PDF

HotFolder
Source Files = Move them to the recycle bin
Unprintable Files = Move them to the recycle bin
PDF printer = to the Above printer
Filter = .pdf Exclude all listed file extensions from conversion

The problem is that when I move a set of files to the hot folder configured above it does not convert all of the files.

For example I move over

image1.jpg
image2.jpg
image3.jpg
image4.jpg
image5.jpg

The result is
image1.pdf
image2.pdf
image4.pdf

When I move over the same set of files again

The results may be the same but random missing file or completes the conversion correctly.

Need help to identify the issue.