Tech junk first:
If the original 4.56 MB JPG was already efficiently compressed (and I am assuming it was), it may have been close to an optimal balance between size and quality specific to its content and resolution. Applying compression again can paradoxically increase the file size since I am most likely introducing a higher quality setting. This occurs because re-encoding an already compressed image to a higher compression setting can introduce new artifacts that the compression algorithm attempts to preserve, thus increasing the file size.
Question:
This was primarily made so I could compress large files (over 10 MB) like the OP is encountering, allowing me to upload them to WikiTree.
It wasn't really designed for files already under 10 MB. But if you gave me details on what controls you wanted to see, and what the expected output would be, I could probably introduce those for you.