Zipping - Custom Pallette Editing (XML)

I am working on creating a custom pallette, and I've learned I can edit the XML file if I save the pallette as a .mpal file. I unzip on a PC by changing the extension from mpal to zip, then exporting, then opening pallette.xml and modifying.

My issue is with re-zipping the file - I don't know how to properly zip the file once I've unzipped it so it will be "accepted" by MS and loaded to the pallettes viewer.

Here is what I've tried:
1. edit and save pallette.xml (e.g. attached has only on change: Palette name="Grace Notes2" (2 added).
2. in windows explorer, select and then right-click on the folder newly named Grace_Notes2 (2 added).
3. choose Send to > Compressed (Zipped) folder.
4. change extension to mpal.
5. in musescore pallette, choose "..." > Load Pallette... and navigate to Grace_Notes2.mpal
6. nothing happens.

Note: the results are the same when I change nothing in the pallette.xml file (Grace_Notes3.mpal has been exported and then re-compressed and also does not work).

Grace_Notes.mpal has had nothing done except changing extension to zip and then back to mpal, with no exporting, and it loads as expected, so the issue is in the extraction or the compression, it seems.

Is there a python script somewhere that compresses the .mpal in a different way than the windows zip way? Where can I find it? Or do I need to write it myself (I hope not!).