DLCs maybe? I guess the zstandard adds some data to decompress the file. Also those really small dlcs are normally a txt file with some lines (txt,json,.data) I saw one that just said "unlock content number 4).
It was proposed to me to add an skip option for files smaller than X size or just dlcs smaller than that size, I'll do in next version.
114kb DLC compress down to 50kb.