ADDTOARCHIVE and ARCHIVE producing different results

I have two buttons to create archives, one for a single and another for multiple.

Copy ADDTOARCHIVE HERE
Copy ARCHIVE=single,keepfolder HERE

If I use the first button on a single folder, then change the extension from zip to cbz, my comic reader views the file fine.

If I use the second button on one or more folders, then change the extension from zip to cbz, my comic reader cannot process the files.

Somehow these two commands are producing different results. Why?

It's difficult for us to guess why your comic reader is having problems with one archive and not the other.

There are some slight differences in how the archives are made by the two commands but they should not cause problems with anything that's using the zip format properly (unless there's a bug or something) and I don't think we have any current reports of them causing problems with anything else.

Your reply is informative, but unfortunately it doesn't help me with my problem...

Is there a way to use the first command to create multiple archives from multiple folders?