Issue has been fixed in InDesign’s latest update, Id 13.1.
Please update your InDesign for the resolution of the problem.
AbhinavSascha Bucher supported this idea ·Sascha Bucher commented
Same problem here. Even the settings for some scripts, if there is one than more file, are not ordered alphabetical in the dropdown from the script dialog. This may is just in combination with High Sierra. But I can not test this right now.