The main problem is that I don't have your data files. Which I would need all of them. All the LibHistorie and all of the GSxxData files which may be too big to post here. In addition to that I would have to manually edit files to replace your user @Name with mine. I may need to do that because it's really not helpful for you to stick with that version. The game will be getting an update and because of the changes you will need the new version. Rather then do all that mess, lets try something else first.
So the only thing I can think of as an alternative is to use the current version and go to the LibGuildStore menu and choose the
Reset LibGuildStore Data as noted in the documentation.
https://esouimods.github.io/3-master...html#ResetData
Once you start that process, then wait for the refresh to finish. LibGuildStore should tell you how much time is remaining. Then see if you see that sale.
The main reason that I will have to have your data if the suggestion doesn't work is because MM does not have a way to display sales for all items except the one you want. I have been resetting my data and testing things for about a week now fixing issues. So I know everything is working (aside from the needed bug-fixes) and I'd have to have your data potentially if the Reset doesn't help.
Also make sure you disable all of the outlier features to test with for now.